Answer:
7/3 is the answer
Step-by-step explanation:
A supervisor records the repair cost for 22 randomly selected VCRs. A sample mean of $75.50 and standard deviation of $18.07 are subsequently computed. Determine the 99% confidence interval for the mean repair cost for the VCRs. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.
Answer:
The t value for 99% CI for 21 df is 2.831.
The critical value that should be used in constructing the confidence interval is (64.593, 86.407).
Step-by-step explanation:
Now the sample size is less than 30 and also population standard deviation is not known.
Then we will use t distribution to find CI
t value for 99% CI for 21 df is TINV(0.01,21)=2.831
The margin of error is [tex]E=t\times\frac{s}{\sqrt{n}}\\\\=2.831\times\frac{18.07}{\sqrt{22}}\\\\=10.907[/tex]
Hence CI is[tex]CI=\overline{x} \pm E\\\\ =75.50 \pm 10.907\\\\=(64.593,86.407 )[/tex]
What constant acceleration is required to increase the speed of a car from 30 miyh to 50 miyh in 5 seconds?
Answer:
The acceleration is 1.8 m/s^2.
Step-by-step explanation:
initial velocity, u = 30 mph = 13.4 m/s
Final velocity, v = 50 mph = 22.4 m/s
time, t = 5 s
Let the acceleration is a.
Use first equation of motion
v = u + at
22.4 = 13.4 + 5 a
a = 1.8 m/s^2
3. Find the minimum number of students needed to guarantee that five of them belong to the same class (Freshman, Sophomore, Junior, Senior)
Answer:
100
Step-by-step explanation:
well you can put 5 students in each class guaranteed 5 times over so it would make sense because 5 for each class 9th-12th 5 times over again and again will eventually give you the answer of 100 5•20
If we take 5 students are in each class.
Then let minimum number of students be x
ATQ
1/20()x = 5
x = 5 × 20
x = 100
Answer: 100 people
Must click thanks and mark brainliest
State if the scenario involves a permutation or a combination. Then find the number of possibilities.
The student body of 290 students wants to elect a president and vice president.
Permutation/Combination:
Answer:
Answer:
Permutation. ; 83810 ways
Step-by-step explanation:
Permutation and combination methods refers to mathematical solution to finding the number of ways of making selection for a group of objects.
Usually, selection process whereby the order of selection does not matter are being treated using permutation, while those which takes the order of selection into cognizance are calculated using combination.
Here, selecting 2 members (president and vice president) from 290 ; since order of arrangement does not matter, we use permutation ;
Recall :
nPr = n! ÷ (n - r)!
Hence,
290P2 = 290! ÷ (290 - 2)!
290P2 = 290! ÷ 288!
290P2 = (290 * 289) = 83810 ways
Let S be a set of linearly dependent vectors in Rn. Select the best statement. A. The set S could, but does not have to, span Rn. B. The set S spans Rn, as long as no vector in S is a scalar multiple of another vector in the set. C. The set S cannot span Rn. D. The set S must span Rn. E. The set S does not span Rn if some vector in S is a scalar multiple of another vector in the set. F. The set S spans Rn, as long as it does not include the zero vector. G. none of the above
Answer:
The set S could, but does not have to, span Rn ( A )
Step-by-step explanation:
Assume S is a set of linearly dependent vectors in Rn
The best statement from the options is ; The set S could, but does not have to, span Rn
This is because S could span Rn ( as stated in option c ) but will not necessary span Rn ( as seen in option D )
Suppose your Unit Quiz grades have been: 85%, 80%, 96%, 72%, 78%, 85% and 92%
a) What is your average/mean score?
b) What is the median score?
c) What is the mode score?
d) Why is the mean lower than the median?
e) What will your mean be if you get a perfect score of 100% on your next quiz?
Answer:
mean: 84
median: 85
mode: 85
explainations for d and e below.
Step-by-step explanation:
mean:
(85+80+96+72+78+85+92)/7 = 544/7 = 84
median:
sort them in order from least to greatest first
72, 78, 80, 85, 85, 92, 96
find the middle number in that order, that's your median. in this case, it's 85.
mode:
number that appears the most in the order; the frequency. in this case as well, it's also 85.
answer for d:
the reason why the mean is lower than the median is because of the fact we were figuring out the average and had to divide, unlike the median where it's just the middle of the order we have.
answer for e:
(85+80+96+72+78+85+92+100)/8 = 644/8 = 80.5%
p.s: please subscribe to #gauthmath# sub reddit if you can for more help.
A building 51 feet tall casts a shadow 48 feet long. Simultaneously, a nearby statue casts a shadow of 16 feet. How tall is the statue? Choose an answer
Answer: 17 feet
Step-by-step explanation:
51/48 = x/16
(51)(16)/48
The statute is 17 feet tall.
What are the similar triangles?Similar triangles are the triangles that have the same shape, but different sizes. The corresponding angles are congruent and the sides are in proportion.
What is the ratio of any two corresponding sides of similar triangles?The ratio of any corresponding sides in two equiangular triangles is always the same.
Let's visualize the situation according to the given question.
AB is the building ,whose height is 51f
BC is the shadow of the building AB, whose length is 48ft.
QR is the shadow of the tower statue, whose length is 16feet.
Let the height of the statue PR be h feet.
In triangle ACB and triangle PRQ
∠ACB = ∠PRQ = 90 degrees
( the objects and shadows are perpendicular to each other)
∠BAC = ∠QPR
( sunray falls on the pole and tower at the same angle, at the same time )
⇒ΔACB similar to ΔPRQ ( AA criterion)
Therefore, the ratio of any two corresponding sides in equiangular triangles is always same.
⇒ AC/CB = PR/RQ
⇒[tex]\frac{51}{48} =\frac{h}{16}[/tex]
⇒ h = [tex]\frac{(51)(16)}{48}[/tex]
⇒ h = 17 feet.
Hence, the statute is 17 feet tall.
Learn more about the similar triangle here:
brainly.com/question/25882965
#SPJ2
Suppose that 25% of people own dogs If you pick three people at random, what
is the probability that they all three own a dog? (Let me add that we don’t know the
populations size so calculate the probability as if the population is infinite.)
Answer:
1/64
Step-by-step explanation:
25% own a dog, so picking one person has a probability of 1/4 (0.25) for that person to own a dog.
picking 3 people means combining (multiplying) the probabilities of the non-overlapping and non-depending events.
picking the third person has 1/4 chance of owning a dog (as the population is "infinite") combined with the chance that also the second pick owned a dog, which has to be combined with the chance of the first pick owning a dog.
so,
1/4 × 1/4 × 1/4 = 1/4³ = 1/64 = 0.015625
f(x) = 1 + 9. Find f '(x) and its domain.
A. f-1 (z) = (x – 9)?: x2 9
B. f-1(x) = (x – 9)?; x20
c. f-1 (2) = x2 – 9;x2 9
D. f-1 (x) = x2 – 9; x2 0
Answer:
B
Step-by-step explanation:
f(x) = sqrt(x) + 9
f(x) - 9=sqrt(x)
f^(-1)(x)=(x-9)^2 and it's domain is greater than 0
Mark is investing $8,000 in an account paying 5.5% interest compounded daily. What will Mark's account balance be in 6 years?
Picture is the answer
A university is interested in promoting graduates of its honors program by establishing that the mean GPA of these graduates exceeds 5.1. A sample of 33 honors students is taken and is found to have a mean GPA equal to 5.2. The population standard deviation is assumed to equal 0.40. The parameter to be tested is ___________________________.
Answer:
B. The mean GPA of the university honors students
Step-by-step explanation:
Parameter in statistical parlance simply refers to numerical characteristics obtijed from the population dataset or observations. The population itself refers to all observations belonging to a particular or specific experiment or research. Here, the population is the all students belonging to the university's honors programme. The measured characteristic is the mean of the student's GPA. THEREFORE, the parameter will be the mean GPA of the honors student.
Compare the functions shown below:
f(x) = 7x + 3 g(x) tangent function with y intercept at 0, 2 h(x) = 2 sin(3x + π) − 1
An auto transport truck holds cars. A car dealer plans to bring in new cars in June and July. If an auto transport truck is filled for each delivery, except for the last one, how many full truckloads are needed and how many cars will be in the last truck?
Answer:
95 truckloads
Last truck = 10 cars
Step-by-step explanation:
Capacity of auto truck = 12 cars
Total number of cars to be brought in = 1150
The number of truckloads required :
Total number of cars to be brought in / capacity of auto truck
Number of truckloads = 1150 / 12 = 95.83333
This means that the number of full truckloads required will be, the whole number = 95
The last truck won't be full and will contain :
1150 - (95 * 12)
1150 - 1140
= 10 cars
A telephone service representative believes that the proportion of customers completely satisfied with their local telephone service is different between the South and the Midwest. The representative's belief is based on the results of a survey. The survey included a random sample of 1300 southern residents and 1380 midwestern residents. 39% of the southern residents and 50% of the midwestern residents reported that they were completely satisfied with their local telephone service. Find the 80% confidence interval for the difference in two proportions. Step 1 of 3 : Find the point estimate that should be used in constructing the confidence interval
Answer:
The point estimate that should be used in constructing the confidence interval is 0.11.
The 80% confidence interval for the difference in two proportions is (0.0856, 0.1344).
Step-by-step explanation:
Before building the confidence interval, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Midwest:
50% of 1380, so:
[tex]p_M = 0.5[/tex]
[tex]s_M = \sqrt{\frac{0.5*0.5}{1380}} = 0.0135[/tex]
South:
39% of 1300, so:
[tex]p_S = 0.39[/tex]
[tex]s_S = \sqrt{\frac{0.39*0.61}{1300}} = 0.0135[/tex]
Distribution of the difference:
[tex]p = p_M - p_S = 0.5 - 0.39 = 0.11[/tex]
So the point estimate that should be used in constructing the confidence interval is 0.11.
[tex]s = \sqrt{s_M^2+s_S^2} = \sqrt{0.0135^2+0.0135^2} = 0.0191[/tex]
Confidence interval:
[tex]p \pm zs[/tex]
In which
z is the z-score that has a p-value of [tex]1 - \frac{\alpha}{2}[/tex].
80% confidence level
So [tex]\alpha = 0.2[/tex], z is the value of Z that has a p-value of [tex]1 - \frac{0.2}{2} = 0.9[/tex], so [tex]Z = 1.28[/tex].
The lower bound of the interval is:
[tex]p - zs = 0.11 - 1.28*0.0191 = 0.0856[/tex]
The upper bound of the interval is:
[tex]p + zs = 0.11 + 1.28*0.0191 = 0.1344[/tex]
The 80% confidence interval for the difference in two proportions is (0.0856, 0.1344).
What is the phase of y= -3cos (3x-pi) +5
Answer:
[tex]- \frac{\pi}{3}[/tex]
Step-by-step explanation:
Given
[tex]y = -3\cos(3x - \pi) + 5[/tex]
Required
The phase
We have:
[tex]y = -3\cos(3x - \pi) + 5[/tex]
Rewrite as:
[tex]y = -3\cos(3(x - \frac{\pi}{3})) + 5[/tex]
A cosine function is represented as:
[tex]y = A\cos(B(x + C)) + D[/tex]
Where:
[tex]C \to[/tex] Phase
By comparison:
[tex]C = - \frac{\pi}{3}[/tex]
Hence, the phase is: [tex]- \frac{\pi}{3}[/tex]
What is the order of rotational symmetry for the figure?
A. 3
B. 2
C. 4 or more
D. 1
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Answer:
C. 4 or more
Step-by-step explanation:
Rotating the figure in increments of 90° will give the same figure. There are 4 such rotations in a full turn. The order of rotational symmetry is 4.
what is the area of a circle if the radius is 9 m
Answer:
(approximately) 254.34 meters
Step-by-step explanation:
Concepts:
Area is the amount of space a 2D shape has.The area of a circle is the amount of space it has. The formula to find the area is πr^2, where r is the radius and π is often represented as 3.14 or 22/7. The radius of a circle is a straight line from the center to the circumference of it. The radius is 1/2 of the diameter, meaning the diameter of a circle is a straight line passing from one side to the other side of the circle.Solving:
Let's use the formula for area of a circle to solve.
1. Formula for Area of a Circle
πr^22. Exchange π for 3.14
3.14 · r^23. Plug in the value of r (radius of circle) as 9
3.14 · 9^24. Simplify
3.14 · 81254.34Therefore, the area of a circle when the radius is 9 meters is approximately 254.34 meters.
The product of two consecutive even integers is 10 less than 5 times their sum. Find the two integers. Answer in
the form of paired points with the lowest of the two integers first.
or
Answer:
(0,2) and (8,10)
Step-by-step explanation:
Let the smaller integer be 2n. The larger will be 2x+2.
ATQ. 2n(2n+2)+10=5(4n+2). Solving it, we get 2n=0 or 2n=8. The pairs are (0,2) and (8,10)
Jenny bought scrapbooking supplies for $156.50. She paid $10.17 in sales tax. What was the sales tax rate on the supplies? If necessary, round your answer to the nearest tenth.
Answer:
6.5%
Step-by-step explanation:
sales price x sales tax rate = sales tax
156.50 x sales tax rate = 10.17
sales tax rate = 10.17/156.50
sales tax rate = .065 or 6.5%
Air-USA has a policy of booking as many as 22 people on an airplane that can only seat 20 people. (Past studies have revealed that only 82% of the booked passengers actually show up for the flight.) a) Find the probability that if Air-USA books 22 people, not enough seats will be available. Round your answer to 4 decimal places. P ( X > 20 )
Answer:
The answer is "0.07404893".
Step-by-step explanation:
Applying the binomial distribution:
[tex]n = 22\\\\p= 82\%=0.82\\\\q = 1-0.82 = 0.18\\\\[/tex]
Calculating the probability for not enough seats:
[tex]=P(X>20)\\\\= P(21) + P(22)\\\\[/tex]
[tex]= \binom{22}{21} (0.82)^{21}(0.18)^1+ \binom{22}{22} (0.82)^{22}(0.18)[/tex]
[tex]=0 .06134598+ 0.01270295\\\\=0.07404893[/tex]
which of the following is a polynomial?
A. 15x^4
B. 6x^2/x
C. 4x^2+9x+12
D. 3- √2x
Answer:
C. 4x^2 + 9x + 12
Step-by-step explanation:
4x^2 + 9x + 12 is a polynomial.
Answer:
the answer is c
Step-by-step explanation:
Simplify the following expression:
(15b^5)^2
—————-
(5b^2)^3
Answer:
5x
Step-by-step explanation:
(75b x)x×2
---------------
(10b x)×3
=75b x×x×2
-----------------
10b x×3
=25x
-------
5
=5x
An ice cream truck started the day with 454545 ice cream sandwiches. During a stop at a busy park they sold sss ice cream sandwiches. After the stop, the truck had 212121 ice cream sandwiches remaining.
Write an equation to describe this situation.
How many ice cream sandwiches did the truck sell at the park?
Answer:
45- s= 21
s= 45- 21
=24
so the answer is 24
Which best describes the relationship between the lines with equations 2x – 9y = 1 and x + 8y = 6?
A. perpendicular
B. neither perpendicular nor parallel
C. parallel
D. same line
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Answer:
B. neither perpendicular nor parallel
Step-by-step explanation:
If the lines were perpendicular, the coefficients would be swapped and one negated. (You would have 8x -y = c, or 9x +2y = c in the system.)
If the lines were parallel, the coefficients in the two equations would only differ by a common factor. (Both equations would reduce to 2x -9y = c, or x +8y = c.)
The lines are not the same line (coefficients are different).
So, the only reasonable description is ...
neither perpendicular nor parallel
find the value of the trigonometric ratio
Answer:
3/5
Step-by-step explanation:
sinA = opposite/hypotenuse = BC/AC = 21/35 = 3/5
Independent simple random samples are selected to test the difference between the means of two populations whose standard deviations are not known. We are unwilling to assume that the population variances are equal. The sample sizes are n1 = 25 and n2 = 35. The correct distribution to use is the:
1) t distribution with 59 degrees of freedom.
2) t distribution with 58 degrees of freedom.
3) t distribution with 61 degrees of freedom.
4) t distribution with 60 degrees of freedom.
Answer:
2) t distribution with 58 degrees of freedom.
Step-by-step explanation:
Population standard deviations not known:
This means that the t-distribution is used to solve this question.
The sample sizes are n1 = 25 and n2 = 35.
The number of degrees of freedom is the sum of the sample sizes subtracted by the number of samples, in this case 2. So
25 + 35 - 2 = 58 df.
Thus the correct answer is given by option 2.
Find the Z scores for which 5% of the distributions area lies between negative Z & Z
Answer:
0.475: Z = -0.062706778
0.525: Z = 0.062706778
Step-by-step explanation:
HELP ASAP
Compare the volume of these two shapes, given the radii are the same.
Answer:
The left cylinder has greater than the right cylinder.
Step-by-step explanation:
Volume of a cylinder is the area of a base times the height.
As the radii are identical, the area of each base is πr²
As the left cylinder has greater height, it also has greater volume.
Question for the kids orrr?
Answer:
B. 18 sq in.
Step-by-step explanation:
Surface area of the triangular pyramid excluding the base = area of the three triangular faces = 3(½ × base × height)
Where,
base = 3 inches
height = ED = 4 inches
Plug in the known values into the equation
Surface area of the triangular pyramid excluding the base = 3(½ × 3 × 4)
= 3(3 × 2)
= 3(6)
= 18 sq in.
In a sociology class there are 14 men and 10 women. 3 students are randomly selected to present a topic. What is the probability that at least 1 of the 3 students selected is female? Express your answer as a fraction or a decimal number rounded to four decimal places.
Answer:
0.8015
Step-by-step explanation:
Hope I'm correct lol
