It’s a math riddle please help Id appreciate it I need this quickly I’ll give additional points... I’d do need an explanation because the question requires it.
Answers
There are three cloaks, so you have to think, what times what equals 21? 7•3=21 after that you just do that formula through the rest 3•10=30
For the last one you have to figure what added and subtracting itself would equal 15? Well it would be 15
15+15-15=15
After that put it all together and you get 157
7+10•15=157
Hope that helps☀️
The puzzle are: 21, 30, 15, 333.
PuzzleClock:
Clock time=9 o'clock+9 o'clock+3 o'clock
Clock time=21
Calculator:
Calculator 1=1+2+3+4=10
Calculator 2=1+2+3+4=10
Calculator 3=1+2+3+4=10
Calculator=10+10+10
Calculator=30
Bulb:
The 3 bulb has 5 light each which represent the brightness of the 3 bulb.
Bulb=15+(15-15)
Bulb =15+0
Bulb=15
Fourth puzzle
Clock+Calculator×Bulb
9 o'clock+(1+2+2+4)× [3 bulb(3 bulb×4 light)]
9+9×(3×12)
Apply BODMAS
9+9×36
9+324
=333
Inconclusion the puzzle are: 21, 30, 15, 333.
Learn more about puzzle here:https://brainly.com/question/16999211
Related Questions
normally distributed with an unknown population mean and a population standard deviation of 4.5 points. A random sample of 45 scores is taken and gives a sample mean of 84. Find a 90% confidence interval
Answers
Answer:
= ( 82.90, 85.10) points
Therefore at 90% confidence interval (a,b)= ( 82.90, 85.10) points
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 84
Standard deviation r = 4.5
Number of samples n = 45
Confidence interval = 90%
z(at 90% confidence) = 1.645
Substituting the values we have;
84+/-1.645(4.5/√45)
84+/-1.645(0.670820393249)
84+/-1.10
= ( 82.90, 85.10) points
Therefore at 90% confidence interval (a,b)= ( 82.90, 85.10) points
What’s the correct explanation for this question?
Answers
Step-by-step explanation:
=> The volume of a triangular pyramid can be found using the formula V = 1/3AH where A = area of the triangle base, and H = height of the pyramid
=> The volume of a cone can be found by V = 1/3(Ab)(H) where Ab is base area and H is the height of the cone
The difference between both is that is it's base. A cone has a polygonal base while a pyramid has a tetragonal base
divide the following polynomials ( 9 x 4 + 3 x 3 y − 5 x 2 y 2 + x y 3 ) ÷ ( 3 x 2 + 2 x 2 y − x y 2 )
Answers
Answer:
2(-2y+9)/3+y
Step-by-step explanation:
Last weekend, Lena worked 7.5 hours on Friday, 9.75 hours on Saturday, and 6.25 hours on Sunday.
She earns £8.60 per hour. How much did she earn in total?
Answers
Answer:202.1
Step-by-step explanation:
7.5hrs +9.75hrs+6.25hrs=23.5
8.60 X 23.5 =202.1 pounds
Bob has 54 more five-dollar bills than ten-dollar bills. The number of five-dollar bills he has
is 7 times that of ten-dollar bills. How many dollars does Bob have in all?
Answers
Answer:5000 sum
Step-by-step explanation:
Having integrated with respect to ϕ and θ, you now have the constant 4π in front of the integral and are left to deal with ∫[infinity]0A21(e−r/a)2r2dr=A21∫[infinity]0r2(e−r/a)2dr.
What is the value of A21∫[infinity]0r2(e−r/a)2dr?Express your answer in terms of A1 and a.
Find the unique positive value of A1.
Express your answer in terms of a and π.
Answers
Answer:
Step-by-step explanation:
[tex]\int\limits^{\infty}_0 {A^2_1} (e^{-r/a})r^2dr= {A^2_1}\int\limits^{\infty}_0r^2(e^{-r/a})^2\, dr)[/tex]
[tex]=A_1^2\int\limits^{\infty}_0 r^2e^{-2r/a}\ dr[/tex]
[tex]=A_1^2[\frac{r^2e^{2r/a}}{-2/a} |_0^{\infty}-\int\limits^{\infty}_0 2r\frac{e^{-2r/a}}{-2/a} \ dr][/tex]
[tex]=A^2_1[0+\int\limits^{\infty}_0 a\ r\ e^{-2r/a}\ dr][/tex]
[tex]=A^2_1[\frac{a \ r \ e^{-2r/a}}{-2/a} |^{\infty}_0-\int\limits^{\infty}_0 \frac{a \ e^{-2r/a}}{-2/a} \ dr][/tex]
[tex]=A_0^2[0-0+\int\limits^{\infty}_0 \frac{a^2}{2} e^{-2r/a}\ dr\\\\=A_1^2\frac{a^2}{2} \int\limits^{\infty}_0 e^{-2r/a}\ dr\\\\=A_1^2\frac{a^2}{2} [\frac{e^{-2r/a}}{-2/a} ]^{\infty}_0[/tex]
[tex]=\frac{A_1^2a^2}{2} -\frac{a}{2} [ \lim_{r \to \infty} [e^{-2r/a} -e^0]\\\\=\frac{A_1^2a^2}{2} -(\frac{a}{2}) (0-1)[/tex]
[tex]=\frac{A_1^2a^3}{4}[/tex]
[tex]\therefore A_1^2\int\limits^{\infty}_0 r^2(e^{-r/a}) \ dr =\frac{A_1^2a^3}{4}[/tex]
Find the unique positive value of A1
[tex]=4\pi (\frac{A_1^2a^3}{4} )\\\\=A_1^2a^3\pi\\\\A_1^2=\frac{1}{a^3\pi} \\\\A_1=\sqrt{\frac{1}{a^3\pi} }[/tex]
Please help me explain your answer only answer if you are sure
Answers
Answer:
The answer of top prism is 262
and down prism is 478
The upper figure is triangular prism.
so, we use bh+2ls+lb formula
B=5
h=3
s=4
l=19
Now,
surface area of triangular prism = bh+2ls+lb
= 5×3+2×19×4+19×5
= 262
The down figure is rectangular prism.
so, we use 2lw+2lh+2hw
l=5
h=6
w=19
Now,
The area of rectangular prism = 2lw+2lh+2hw
= 2×5×19+2×19×6+2×5×6
= 478
Let uequalsleft angle 4 comma negative 3 right angle, vequalsleft angle negative 2 comma 5 right angle, and wequalsleft angle 0 comma negative 6 right angle. Express 7 Bold u minus 5 Bold v plus Bold w in the form left angle a comma b right angle.
Answers
Answer:
[tex]<38,52>[/tex]
Step-by-step explanation:
[tex]u=<4,-3>\\v=<-2,5>\\w=<0,-6>[/tex]
We are required to express 7u-5v+w in the form <a,b>.
[tex]7u-5v+w =7<4,-3>-5<-2,5>+<0,-6>\\=<28,-21>-<-10,25>+<0,-6>\\=<28-(-10)+0, -21-25-6>\\=<38,52>\\$Therefore:$\\7u-5v+w=<38,52>[/tex]
A bottler of drinking water fills plastic bottles with a mean volume of 1,007 milliliters (mL) and standard deviation The fill volumes are normally distributed. What proportion of bottles have volumes less than 1,007 mL?
Answers
Answer:
0.5 = 50% of bottles have volumes less than 1,007 mL
Step-by-step explanation:
Problems of normally distributed samples are solved using the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
In this question, we have that:
[tex]\mu = 1007[/tex]
What proportion of bottles have volumes less than 1,007 mL?
This is the pvalue of Z when X = 1007. So
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{1007 - 1007}{\sigma}[/tex]
[tex]Z = 0[/tex]
[tex]Z = 0[/tex] has a pvalue of 0.5
0.5 = 50% of bottles have volumes less than 1,007 mL
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answers
Answer:
B. F(x) = 3(x - 2)² - 2
Step-by-step explanation:
→The function F(x) narrowed, meaning the absolute value being multiplied to the function is greater than 1.
→The function F(x) flipped over the x-axis, this means that the number being multiplied has to be a negative.
→The function F(x) shifted to the left 2 units, this means there needs to be a 2 being added.
→The function F(x) shifted downwards 2 units, meaning there needs to be a 2 being subtracted from the whole function.
This gives us the correct answer of "B. F(x) = 3(x - 2)² - 2."
Four men are to divide K500 equally among them. When the money was given, 20% was taken away.
How much each did the four men receive?
Answers
Answer: 20% of 500= 100
So 500-100 = 400
4x100= 400
Step-by-step explanation:
. Suppose that only 20% of all drivers come to a complete stop at an intersection having flashing lights in all directions when no other cars are visible. What is the probability that, of 15 randomly chosen drivers coming to an intersection under these conditions,
Answers
Answer:
a. P(x≤9)=0.9999
b. P(x=6)=0.0430
c. P(x≥6)=0.0611
Step-by-step explanation:
The question is incomplete:
a.At most 9 will come to a complete stop?
b.Exactly 6 will come to a complete stop?
c.At least 6 will come to a complete stop?
d.How many of the next 20 drivers do you expect to come to a complete stop?
The amount of drivers from the sample that will come to a complete stop can be modeled by a binomial random variable with n=15 and p=0.2.
The probability that exactly k drivers from the sample come to a complete stop is:
[tex]P(x=k) = \dbinom{n}{k} p^{k}q^{n-k}[/tex]
a. We have to calculate the probability that at most 9 come to a complete stop:
[tex]P(x\leq9)=\sum_{k=0}^9P(x=k)\\\\\\P(x=0) = \dbinom{15}{0} p^{0}q^{15}=1*1*0.0352=0.0352\\\\\\P(x=1) = \dbinom{15}{1} p^{1}q^{14}=15*0.2*0.044=0.1319\\\\\\P(x=2) = \dbinom{15}{2} p^{2}q^{13}=105*0.04*0.055=0.2309\\\\\\P(x=3) = \dbinom{15}{3} p^{3}q^{12}=455*0.008*0.0687=0.2501\\\\\\P(x=4) = \dbinom{15}{4} p^{4}q^{11}=1365*0.0016*0.0859=0.1876\\\\\\P(x=5) = \dbinom{15}{5} p^{5}q^{10}=3003*0.0003*0.1074=0.1032\\\\\\P(x=6) = \dbinom{15}{6} p^{6}q^{9}=5005*0.0001*0.1342=0.043\\\\\\[/tex]
[tex]P(x=7) = \dbinom{15}{7} p^{7}q^{8}=6435*0*0.1678=0.0138\\\\\\P(x=8) = \dbinom{15}{8} p^{8}q^{7}=6435*0*0.2097=0.0035\\\\\\P(x=9) = \dbinom{15}{9} p^{9}q^{6}=5005*0*0.2621=0.0007\\\\\\P(x\leq9)=0.0352+0.1319+0.2309+0.2501+0.1876+0.1032+0.043+0.0138+0.0035+0.0007\\\\P(x\leq9)=0.9999[/tex]
b. We have to calculate the probability that exactly 6 will come to a complete stop:
[tex]P(x=6) = \dbinom{15}{6} p^{6}q^{9}=5005*0.0001*0.1342=0.043\\\\\\[/tex]
c. We have to calculate the probability that at least 6 will come to a complete stop:
[tex]P(x\geq6)=\sum_{k=6}^{15}P(x=k)\\\\\\P(x=6) = \dbinom{15}{6} p^{6}q^{9}=5005*0.0001*0.1342=0.043\\\\\\P(x=7) = \dbinom{15}{7} p^{7}q^{8}=6435*0*0.1678=0.0138\\\\\\P(x=8) = \dbinom{15}{8} p^{8}q^{7}=6435*0*0.2097=0.0035\\\\\\P(x=9) = \dbinom{15}{9} p^{9}q^{6}=5005*0*0.2621=0.0007\\\\\\P(x=10) = \dbinom{15}{10} p^{10}q^{5}=3003*0*0.3277=0.0001\\\\\\P(x=11) = \dbinom{15}{11} p^{11}q^{4}=1365*0*0.4096=0\\\\\\P(x=12) = \dbinom{15}{12} p^{12}q^{3}=455*0*0.512=0\\\\\\[/tex]
[tex]P(x=13) = \dbinom{15}{13} p^{13}q^{2}=105*0*0.64=0\\\\\\P(x=14) = \dbinom{15}{14} p^{14}q^{1}=15*0*0.8=0\\\\\\P(x=15) = \dbinom{15}{15} p^{15}q^{0}=1*0*1=0\\\\\\P(x\geq6)=0.043+0.0138+0.0035+0.0007+0.0001+0+0+0+0\\\\P(x\geq6)=0.0611[/tex]
The sum of three numbers is 10. Two times the second number minus the first number is equal to 12. The first number minus the second number plus twice the third number equals 7. Find the numbers. Listed in order from smallest to largest, the numbers are , , and .
Answers
Answer:
[tex]x =\frac{14}{3} , y = \frac{25}{3} and z = -3[/tex]
The numbers are [tex]-3 ,\frac{14}{3} , \frac{25}{3}[/tex]
Step-by-step explanation:
Step(i):-
Given sum of the three numbers is 10
Let x , y , z be the three numbers is 10
x +y + z = 10 ...(i)
Given two times the second number minus the first number is equal to 12
2 × y - x = 12 ...(ii)
Given the first number minus the second number plus twice the third number equals 7
x + y + 2 z = 7 ...(iii)
Step(ii):-
Solving (i) and (iii) equations
x + y + z = 10 ...(i)
x + y + 2 z = 7 .. (iii)
- - - -
0 0 -z = 3
Now we know that z = -3 ...(a)
from (ii) equation
2 × y - x = 12 ...(ii)
x = 2 y -12 ...(b)
Step(iii):-
substitute equations (a) and (b) in equation (i)
x+y+z =10
2 y - 12 + y -3 =10
3 y -15 =10
3 y = 10 +15
3 y =25
[tex]y = \frac{25}{3}[/tex]
Substitute [tex]y = \frac{25}{3}[/tex] and z = -3 in equation(i) we will get
x+y+z =10
[tex]x + \frac{25}{3} -3 = 10[/tex]
[tex]x +\frac{25-9}{3} = 10[/tex]
[tex]x +\frac{16}{3} = 10[/tex]
[tex]x = 10 - \frac{16}{3}[/tex]
[tex]x = \frac{30 -16}{3} = \frac{14}{3}[/tex]
Final answer :-
[tex]x =\frac{14}{3} , y = \frac{25}{3} and z = -3[/tex]
The numbers are [tex]-3 ,\frac{14}{3} , \frac{25}{3}[/tex]
Answer:
-2, 5, 7 on Edge.
Step-by-step explanation:
I got the Answer right.
Please answer this correctly
Answers
Answer:
12 2/5 hours
Step-by-step explanation:
[tex]1+1+1\frac{1}{5} +1\frac{1}{5} +1\frac{1}{5} +1\frac{3}{5} +1\frac{3}{5} +1\frac{4}{5} +1\frac{4}{5} =\\\\2+3\frac{3}{5} +3\frac{1}{5} +3\frac{3}{5} =\\\\11\frac{7}{5} =\\\\12\frac{2}{5}[/tex]
12 2/5 hours have been logged in all.
PLZ PLZ HELP ME I NEED THIS FOR ONE OF MY FIANLE ASSIGNMENTS OF THE YEAR AND WHOEVER ANSWERS CORRECTLY WILL GET BRAINLEST
Answers
5×4=20 is closer to 24.9344.
[tex]487 \times 512=24.9344[/tex]
Let's try placing the decimals after the hundreds place.
[tex]4.87 \times 5.12=24.9344[/tex]
It works.
There is more than one possibility.
[tex].487 \times 51.2=24.9344[/tex]
[tex]48.7 \times .512=24.9344[/tex]
the sum of the three numbers in 2003,two of the numbers are 814 and 519 what is the third number
Answers
Answer:
idk dont ask me
Step-byi-step explanation:
Answer:
a+b+c=2003
a+b=814
2003-819=189
Step-by-step explanation:
Please help me with this question!!!
Answers
Answer:
3(cos(75°) +i·sin(75°)) and 3(cos(255°) +i·sin(255°))
Step-by-step explanation:
Using Euler's formula, this can be written as ...
x^2 = 9·e^(i5π/6)
Then the square roots are ...
x = (±√9)e^((i5π/6)/2) = ±3e^(i5π/12)
Of course, multiplying by -1 is the same as adding 180° to the angle.
The square roots are ...
3(cos(75°) +i·sin(75°)) and 3(cos(255°) +i·sin(255°))
g Question 6 1 pts A 3x3 matrix with real entries can have (select ALL that apply) Group of answer choices three eigenvalues, all of them real. three eigenvalues, all of them complex. two real eigenvalues and one complex eigenvalue. one real eigenvalue and two complex eigenvalues. only two eigenvalues, both of them real. only two eigenvalues, both of them complex. only one eigenvalue -- a real one. only one eigenvalue -- a complex one.
Answers
Answer:
(A)three eigenvalues, all of them real.
(D)one real eigenvalue and two complex eigenvalues.
(G)only one eigenvalue -- a real one.
Step-by-step explanation:
Given an [tex]n \times n[/tex] matrix, the characteristic polynomial of the matrix is the degree n polynomial in one variable λ:
[tex]p(\lambda) = det(\lambda I- A)[/tex]
If such [tex]n \times n[/tex] matrix A has real entries, its complex eigenvalues will always occur in complex conjugate pairs.
Therefore, for a [tex]3 \times 3[/tex] matrix with real entries, the following are possible:
(A)three eigenvalues, all of them real.
(D)one real eigenvalue and two complex eigenvalues.
(G)only one eigenvalue -- a real one.
A [tex]3 \times 3[/tex] matrix with real entries cannot have the following:
(B)three eigenvalues, all of them complex.
(C)two real eigenvalues and one complex eigenvalue.
(E)only two eigenvalues, both of them real.
(F)only two eigenvalues, both of them complex.
(H)only one eigenvalue -- a complex one.
I WILLL GIVE BRAINLIEST ANSWER ASAP
Answers
Answer: 2ND ONE
Step-by-step explanation:
Answer:
-3
Step-by-step explanation:
5x+3=4x
5x-4x=-3
x=-3
Edit: Check by plugging in x = -3
5(-3)+3=4(-3)
-15+3=-12
-12=-12✅
In 2018, the number of students at The Villages High School was 975 and is increasing at a rate of 2.5% per year. Write and use an exponential growth function to project the populating in 2025. Round to the nearest whole number. Help plzzz
Answers
Answer:
[tex]A(t)=975(1.025)^t[/tex]
In 2025,the number of students at the villages high school=1159
Step-by-step explanation:
We are given that in 2018
Number of students at the villages high school=975
Increasing rate,r=2.5%=0.025
We have to write and use of exponential growth function to project the populating in 2025.
[tex]A_0=975,t=0[/tex]
According to question
Number of students at the villages high School is given by
[tex]A(t)=A_0(1+r)^t[/tex]
Substitute the values
[tex]A(t)=975(1+0.025)^t=975(1.025)^t[/tex]
t=7
Substitute the value
Then, the number of students at the villages high school in 2025
[tex]A(7)=975(1.025)^7=1158.96\approx 1159[/tex]
Answer:
1,159 students
Step-by-step explanation:
the exponential growth rate formula:
A = P ( 1 + r)ⁿ
A = amount after growth = ??P = current/original amount = 975 studentsr = yearly growth rate = 2.5% or 0.025n = number of years = 2025 - 2018 = 7Pop. 2025 = 975 (1 + 0.025)⁷
Pop. 2025 = 975 x 1.025⁷ = 1,158.97 ≈ 1,159 students
Consider the following dice game, as played at a certain gambling casino: players 1 and 2 roll a pair of dice in turn. the bank then rolls the dice to determine the outcome according to the following rule: player i,i=1,2, wins if his roll is strictly
Ii={1 if i wins, 0 otherwise}
and show that I1 and I2 are positively correlated. Explain why this result was to be expected.
Answers
Answer:
they are positively correlated.
Step-by-step explanation:
We can calculate the individal expectations first. FIrst player will win if that player's roll is greater than the bank's roll. There are (6 possible rolls of player 1 * 6 possible rolls of bank =) 36 total possible rolls, out of which player 1 will win in 15 cases.
[tex]\therefore E(I_i) = 1\cdot \frac{15}{36} + 0 \cdot \frac{21}{36} = \frac{5}{12} \approx 0.4167[/tex]
For the joint expectation, there are (6 possible rolls of player 1 * 6 possible rolls of player 2 * 6 possible rolls of bank =) 216 total possible rolls.
Cases where both players win: Expectation = $2.
If bank rolls 1, both players will win in 5*5 = 25 cases. P1 is one of {2,3,4,5,6}, P2 is one of {2,3,4,5,6}
If bank rolls 2, both players will win in 4*4 = 16 cases.
If bank rolls 3, both players will win in 3*3 = 9 cases.
If bank rolls 4, both players will win in 2*2 = 4 cases.
If bank rolls 5, both players will win in 1*1 = 1 cases.
If bank rolls 6, both players will win in 0*0 = 0 cases.
Total cases = 25+16+9+4+1+0 = 55 cases.
Cases where player 1 wins $1 and player 2 loses: Expectation = $1.
If bank rolls 1, player 1 will win and player 2 will lose in 5*1 = 5 cases. P1 is one of {2,3,4,5,6}, P2 is {1}
If bank rolls 2, player 1 will win and player 2 will lose in 4*2 = 8 cases.
If bank rolls 3, player 1 will win and player 2 will lose in 3*3 = 9 cases.
If bank rolls 4, player 1 will win and player 2 will lose in 2*4 = 8 cases.
If bank rolls 5, player 1 will win and player 2 will lose in 1*5 = 5 cases.
If bank rolls 6, player 1 will win and player 2 will lose in 0*6 = 0 cases.
Total cases = 5+8+9+8+5+0 = 35
Cases where player 2 wins $1 and player 1 loses: Expectation = $1.
This is the same as above with player 1 and 2 exchanged.
Total cases = 35
Cases where both players lose: Expectation = $0.
If bank rolls 1, both players will lose in 1*1 = 1 cases. P1 is {1}, P2 is {1}
If bank rolls 2, both players will lose in 2*2 = 4 cases.
If bank rolls 3, both players will lose in 3*3 = 9 cases.
If bank rolls 4, both players will lose in 4*4 = 16 cases.
If bank rolls 5, both players will lose in 5*5 = 25 cases.
If bank rolls 6, both players will lose in 6*6 = 36 cases.
Total cases = 1+4+9+16+25+36 = 91 cases.
Total of all cases (we expect this to be 216 as mentioned above) = 55+35+35+91=216
So, joint expectation is:
[tex]E(I_1I_2) = \frac{2\cdot 55 +1\cdot 35+1\cdot 35+0\cdot 91}{216} = \frac{180}{216}= \frac{5}{6} \approx 0.8333[/tex]
So, the covariance is given by:
[tex]\texttt{Cov}(I_1I_2) =E(I_1I_2) -E(I_1)\cdot E(I_2)= \frac{5}{6}-\frac{5}{12}\cdot\frac{5}{12}=\frac{95}{144} \approx 0.6597[/tex]
As this is greater than 0 and closer to 1, they are positively correlated.
The reason why this result is expected is because the same bank roll is being used for both players. So, it is very likely that both players will win if the bank roll is 1 or even 2. Also, it is very likely that both players will lose if the bank roll is 6, 5, or even 4. This shows positive correlation between the events.
help asap, will get branliest !!
Answers
Answer:
D
Step-by-step explanation:
Lines EF and GH are already parallel. Translating them 2 units to the side without changing how far apart they are vertically means they won't intersect and will remain the same distance apart.
Answer:
D
Step-by-step explanation:
They are parallel lines
Some college professors make bound lecture notes available to their classes in an effort to improve teaching effectiveness. A study of business student's opinions of lecture notes. Two groups of students were surveyed - 86 students enrolled in a promotional strategy class that required the purchase of lecture notes, and 35 students enrolled in a sales/retailing elective that did not offer lecture notes. At the end of the semester :"Having a copy of the lecture notes was helpful in understanding the material." Responses were measured on a nine-point semantic difference scale, where 1="strongly disagree" and 9=" strongly agree." A summary of the results is reported in the follow:
Classes Buying Lecture Notes Classes Not Buying Lecture Notes
n1=86 n2=35
X1=8.48 X2=7.80
S21=.94 S22=2.99
a. Describe the two populations involved in the comparison.
b. Do the samples provides sufficient evidence to conclude that there is a difference in the mean responses of the two groups of the students? Test using α=.01
c. Construct a 99% confidence interval for (μ1-μ2). Interpret the result.
d. Would a 95% confidence interval for (μ1-μ2) be narrow or wider than the one you found in part c? Why?
Answers
Answer:
Step-by-step explanation:
a) The number of students sampled in both populations are large. We can assume that the populations are normally distributed. The populations are also independent.
b) This is a test of 2 independent groups. Let μ1 be the mean responses of students buying lecture notes and μ2 be the mean responses of students not buying lecture notes.
The random variable is μ1 - μ2 = difference in the mean responses of students buying lecture notes and the mean responses of students not buying lecture notes.
We would set up the hypothesis.
The null hypothesis is
H0 : μ1 = μ2 H0 : μ1 - μ2 = 0
The alternative hypothesis is
H1 : μ1 ≠ μ2 H1 : μ1 - μ2 ≠ 0
This is a two tailed test.
Since sample standard deviation is known, we would determine the test statistic by using the t test. The formula is
(x1 - x2)/√(s1²/n1 + s2²/n2)
From the information given,
x1 = 8.48
x2 = 7.8
s1 = 0.94
s2 = 2.99
n1 = 86
n2 = 35
t = (8.48 - 7.8)/√(0.94²/86 + 2.99²/35)
t = 1.32
The formula for determining the degree of freedom is
df = [s1²/n1 + s2²/n2]²/(1/n1 - 1)(s1²/n1)² + (1/n2 - 1)(s2²/n2)²
df = [0.94²/86 + 2.99²/35]²/[(1/86 - 1)(0.94²/86)² + (1/35 - 1)(2.99²/35)²] = 0.0706/0.00192021883
df = 37
We would determine the probability value from the t test calculator. It becomes
p value = 0.195
c) Since alpha, 0.01 < than the p value, 0.195, then we would fail to reject the null hypothesis. Therefore, at 5% significance level, the samples do not provide sufficient evidence to conclude that there is a difference in the mean responses of the two groups of the students.
d) The formula for determining the confidence interval for the difference of two population means is expressed as
Confidence interval = (x1 - x2) ± z√(s²/n1 + s2²/n2)
For a 99% confidence interval, the z score is 1.2.58. This is determined from the normal distribution table.
x1 - x2 = 8.48 - 7.8 = 0.68
z√(s1²/n1 + s2²/n2) = 2.58√(0.94²/86 + 2.99²/35) = 1.33
The confidence interval is
0.68 ± 1.33
The upper boundary for the confidence interval is
0.68 + 1.01 = 2.01
The lower boundary for the confidence interval is
0.68 - 1.33 = - 0.65
We are confident that the difference in population means responses between the students buying lecture notes and the students not buying lecture notes is between - 0.65 and 2.01
d) For a 95% confidence interval, the z score is 1.96.
z√(s1²/n1 + s2²/n2) = 1.96√(0.94²/86 + 2.99²/35) = 1.01
The confidence interval is
0.68 ± 1.01
The upper boundary for the confidence interval is
0.68 + 1.01 = 1.69
The lower boundary for the confidence interval is
0.68 - 1.01 = - 0.33
Therefore, a 95% confidence interval for (μ1-μ2) would be narrower. This is seen in the values in both scenarios.
Solve the equation.
3(x + 1)-1=3x+2
Answers
Answer:
0=0
Step-by-step explanation:Let's solve your equation step-by-step.
3(x+1)−1=3x+2
Step 1: Simplify both sides of the equation.
3(x+1)−1=3x+2
(3)(x)+(3)(1)+−1=3x+2(Distribute)
3x+3+−1=3x+2
(3x)+(3+−1)=3x+2(Combine Like Terms)
3x+2=3x+2
3x+2=3x+2
Step 2: Subtract 3x from both sides.
3x+2−3x=3x+2−3x
2=2
Step 3: Subtract 2 from both sides.
2−2=2−2
0=0
mp
3x+3-1=3x+2
Cancel each terms on each side
3-1=2
Subtract the numbers
2=2
The statement is true for any value of X
Let f(x)=−9x+1. Match the function with the description.
The graph of g is a reflection in the y-axis of the graph of f.
The graph of g is a reflection in the x-axis of the graph of f.
The graph of g is a horizontal translation 16 units right of the graph of f.
The graph of g is a vertical translation 16 units down of the graph of f.
Answers
Answer:
I guess that we want to find the function g(x) for the 4 cases.
first, f(x) = -9*x + 1.
a) The graph of g is a reflection in the y-axis of the graph of f.
First remember: if we have the point (x,y) and we reflect it over the y-axis, we get (-x,y)
then g(x) = f(-x) = -9*-x + 1 = 9*x + 1.
b) The graph of g is a reflection in the x-axis of the graph of f.
if we have a point (x, y) and we reflect it over the x-axis, the point transforms into (x, -y)
then we have: g(x) = -f(x) = 9*x - 1
c) The graph of g is a horizontal translation 16 units right of the graph of f.
When we want to have a translation in the x-axis, we must change x by x - A.
If A is positive, this transformation moves the graph by A units to the right, in this case, A = 16.
g(x) = f(x - 16) = -9*(x - 16) + 1
d) The graph of g is a vertical translation 16 units down of the graph of f.
For vertical translations, if we want to move the graph by A units down (A positive) we should do y = f(x) - A
In this case, A = 16.
then: g(x) = f(x) - 16 = -9*x + 1 - 16 = -9*x - 15.
What is the simplified value of the exponential expression 27 1/3?
1/3
1/9
3
9
Answers
Answer:3
Step-by-step explanation:
Answer:
C.3
Step-by-step explanation:
A hot dog has about 1/4 the amount of protein as 3 ounces of hamburger. Together, they have about 25 grams of protein. How many grams of protein are in a 3 oz hamburger?
Answers
Answer:
(1) protein in hot dog = ¼ * protein in 3 ounces of hamburger
(2) protein in hot dog + protein in 3 ounces of hamburger = 25
So we need to re-arrange (1) and (2) to solve for the protein in 3 ounces of hamburger!
(re-arrange (1)): 4 * protein in hot dog = protein in 3 ounces of hamburger
(re-arrange (2)): protein in hot dog = 25 - protein in 3 ounces of hamburger
(plugging re-arranged (2) into re-arranged (1)):
4 * (25 - protein in 3 ounces of hamburger) = protein in 3 ounces of hamburger ( multiplying )
100- 4 protein in 3 ounces of hamburger = protein in 3 ounces of hamburger
solving for the protein in 3 ounces of hamburger:
5 * protein in 3 ounces of hamburger = 100
protein in 3 ounces of hamburger = 20 gram
Solve 5x^2+3x-4=0 for x using quadratic formula
Answers
Answer:
Step-by-step explanation:That would be the answer
please help! ill give 24 points just tryna finish before the last day
Answers
Answer:
(1,3)
Step-by-step explanation:
Note that the solution for a graphed system of equations is just the point where the two lines intersect.
A point is (x coordinate, y coordinate).
This said, we can find the point where it intersects then see which value it is above for the x axis.
It is directly above 1.
So the x coordinate is 1.
Now, let's look at what coordinate it is next to on the y axis.
It would be 3.
So the y coordinate is 3.
Therefore, the solution to the system of equations graphed below is (1,3)
The length of a field is twice it's breadth. If the length is 30cm. Calculate the perimeter of the field.
Answers
Answer:
b=30/2=15
peri= 90
Step-by-step explanation:
