Step-by-step explanation:
7 times a certain number :
Let the unknown number be x
[tex]7 \times x[/tex]
is less four times that same number -2 is 58 :
7x - 4x -2 = 58
Collect like terms
7x-4x = 58+2
3x = 60
3x/3 = 60/3
x = 20
Let the number be x
ATQ
[tex]\\ \sf\longmapsto 7x-4x-2=58[/tex]
[tex]\\ \sf\longmapsto 3x-2=58[/tex]
[tex]\\ \sf\longmapsto 3x=58+2[/tex]
[tex]\\ \sf\longmapsto 3x=60[/tex]
[tex]\\ \sf\longmapsto x=\dfrac{60}{3}[/tex]
[tex]\\ \sf\longmapsto x=20[/tex]
Simplify Square root (150n^2)
Answer:
12
Step-by-step explanation:
Students in a statistics class are conducting a survey to estimate the mean number of units students at their college are enrolled in. The students collect a random sample of 48 students. The mean of the sample is 12.4 units. The sample has a standard deviation of 1.7 units.
Required:
What is the 95% confidence interval for the average number of units that students in their college are enrolled in?
Answer:
[11.906 ; 12.894]
Step-by-step explanation:
Given :
Sample mean, xbar = 12.4
Sample standard deviation, s = 1.7
Sample size, n = 48
We use the T distribution since we are using the sample standard deviation;
α - level = 95% ; df = n - 1 = 48 - 1 = 47
Tcritical = T(1 - α/2), 47 = 2.012
Using the confidence interval for one sample mean
Xbar ± Tcritical * s/√n
12.4 ± (2.012 * 1.7/√48)
12.4 ± 0.4936922
C. I = [11.906 ; 12.894]
If p is a given sample proposition n is the sample size, and a is the number of standard deviations at a confidence level, what is the standard error of the proportion?
Answer:
The standard error of a proportion p in a sample of size n is given by: [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Step-by-step explanation:
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]
In this question:
The standard error of a proportion p in a sample of size n is given by: [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
What is a corresponding pair for f(-7)=5
Answer:
An ordered pair for a function f(x) looks like (x, f(x)). So the ordered pair here would be (5, f(5)) or (5, 7). Either one would work, as they are the same.
Find two power series solutions of the given differential equation about the ordinary point x = 0. Compare the series solutions with the solutions of the differential equation obtained using the method of Section 4.3. Try to explain any differences between the two forms of the solution. y'' − y' = 0 y1 = 1 − x2 2! + x4 4! − x6 6! + and y2 = x − x3 3! + x5 5! − x7 7! + y1 = x and y2 = 1 + x + x2 2! + x3 3! + y1 = 1 + x2 2! + x4 4! + x6 6! + and y2 = x + x3 3! + x5 5! + x7 7! + y1 = 1 + x and y2 = x2 2! + x3 3! + x4 4! + x5 5! + y1 = 1 and y2 = x + x2 2! + x3 3! + x4 4! +
You're looking for a solution in the form
[tex]y(x) = \displaystyle \sum_{n=0}^\infty a_nx^n[/tex]
Differentiating, we get
[tex]y'(x) = \displaystyle \sum_{n=0}^\infty na_nx^{n-1} = \sum_{n=1}^\infty na_nx^{n-1} = \sum_{n=0}^\infty (n+1)a_{n+1}x^n[/tex]
[tex]y''(x) = \displaystyle \sum_{n=0}^\infty (n+1)na_{n+1}x^{n-1} = \sum_{n=1}^\infty (n+1)na_{n+1}x^{n-1} = \sum_{n=0}^\infty (n+2)(n+1)a_{n+2}x^n[/tex]
Substitute these for y' and y'' in the differential equation:
[tex]\displaystyle \sum_{n=0}^\infty (n+2)(n+1)a_{n+2}x^n - \sum_{n=0}^\infty (n+1)a_{n+1}x^n = 0[/tex]
[tex]\displaystyle \sum_{n=0}^\infty \bigg((n+2)(n+1)a_{n+2}-(n+1)a_{n+1}\bigg)x^n = 0[/tex]
Then the coefficients of y are given by the recurrence
[tex]\begin{cases}a_0=y(0)\\a_1=y'(0)\\a_{n+2}=\frac{a_{n+1}}{n+2}&\text{for }n\ge0\end{cases}[/tex]
or
[tex]a_n = \dfrac{a_{n-1}}n[/tex]
But we cannot assume that [tex]a_0[/tex] and [tex]a_1[/tex] depend on each other; we can only guarantee that the recurrence holds for n ≥ 1, so that
[tex]a_2=\dfrac{a_1}2 \\\\ a_3=\dfrac{a_2}3=\dfrac{a_1}{3\times2} \\\\ a_4=\dfrac{a_3}4=\dfrac{a_1}{4\times3\times2} \\\\ \vdots \\\\ a_n=\dfrac{a_1}{n!}[/tex]
So in the power series solution, we split off the constant term and we're left with
[tex]y(x) = a_0 + a_1 \displaystyle \sum_{n=1}^\infty \frac{x^n}{n!}[/tex]
so that the fundamental solutions are
[tex]y_1=1[/tex]
and
[tex]y_2=x+\dfrac{x^2}{2!}+\dfrac{x^3}{3!}+\dfrac{x^4}{4!}+\cdots[/tex]
Determine whether the following polygons are similar. If yes, type 'yes' in the Similar box and type in the similarity statement and scale factor. If no, type 'None' in the blanks. For the scale factor, please enter a fraction. Use the forward dash (i.e. /) to create a fraction (e.g. 1/2 is the same as 12
1
2
).
Given:
The figures of two polygons.
To find:
Whether the polygons are similar and then find the scale factor (if similar).
Solution:
From the given figures it is clear that both polygons are rectangles and their all interior angles are right angles.
The ratio of their longer sides:
[tex]\dfrac{32}{26}=\dfrac{16}{13}[/tex]
The ratio of their shorter sides:
[tex]\dfrac{18}{12}=\dfrac{3}{2}[/tex]
Since the ratio of their corresponding sides are not equal, therefore the two polygons are not similar.
Therefore the required solutions are:
Similar : No
Similarity statement : None
Scale factor : None
find the missing length indicated
============================================================
Explanation:
Let y be the length of the vertical dashed red line in the drawing. More specifically, this dashed line is an altitude.
Along the top, the entire segment is 400 units long. The right piece is 144 units long, so the left piece is 400-144 = 256 units long.
The triangles are similar, allowing us to set up a proportion like so:
144/y = y/256
144*256 = y*y
36864 = y^2
y^2 = 36864
y = sqrt(36864)
y = 192
So this is the length of that vertical dashed red line.
--------------------------------
Now shift your attention solely on the smaller triangle on the right side. It is a right triangle with legs 144 and 192. The hypotenuse is x.
We can use the pythagorean theorem to find x.
a^2 + b^2 = c^2
c = sqrt( a^2 + b^2 )
x = sqrt( 144^2 + 192^2 )
x = 240
240.
Let y be the length of the vertical dashed red line in the drawing. More specifically, this dashed line is an altitude.
Along the top, the entire segment is 400 units long. The right piece is 144 units long, so the left piece is 400-144 = 256 units long.
The triangles are similar, allowing us to set up a proportion like so:
144/y = y/256
144*256 = y*y
36864 = y^2
y^2 = 36864
y = sqrt(36864)
y = 192
So this is the length of that vertical dashed red line.
Now shift your attention solely to the smaller triangle on the right side. It is a right triangle with legs 144 and 192. The hypotenuse is x.
We can use the Pythagorean theorem to find x.
a^2 + b^2 = c^2
c = sqrt( a^2 + b^2 )
x = sqrt( 144^2 + 192^2 )
x = 240
What is Pythagorean Theorem?Pythagorean theorem, the well-known geometric theorem that the sum of the squares on the legs of a right triangle is equal to the square on the hypotenuse (the side opposite the right angle)—or, in familiar algebraic notation, a2 + b2 = c2.
Learn more about the Pythagorean theorem at
https://brainly.com/question/343682
#SPJ2
If a over 2 equals b over 3 then b over a equals what?
A car is advertised with a price of $16336. The payment plan to own a car is $474 per month for 8 years. What is the
amount of interest paid?
find the value of trigonometric ratio
1. Carlos wants to deposit $900 into savings accounts at three different
banks: Bank of Chance, Merchant Bank, and Utopian Financing. He will
deposit two times as much into Merchant Bank as Bank of Chance
because they offer a higher interest rate. He also expects the Utopian
Financing deposit to be only 20% of the total of the other two deposits.
How much will Carlos deposit into the Utopian Financing savings account
(4 points)
O $180
$250
$500
$150
Answer:
$150
Step-by-step explanation:
0.2 X 750 = 150
hope this helps
A noted psychic was tested for extrasensory perception. The psychic was presented with 200 cards face down and asked to determine if each card were one of five symbols: a star, a cross, a circle, a square, or three wavy lines. The psychic was correct in 50 cases. Let p represent the probability that the psychic correctly identifies the symbol on the card in a random trial. Assume the 200 trials can be treated as a simple random sample from the population of all guesses the psychic would make in his lifetime. How large a sample n would you need to estimate p with a margin of error of 0.01 with 95% confidence? Use the hypothesized value p = 0.20 as the value for p*.
Answer:
r3jehejn wbbwbwbbwmwkwkwjwjwhhejehehehhe
Fo quality control purposes, we collect a sample of 300 items and find 36 defective items in it. Construct a 90% confidence interval [a, b] for the proportion of defective items in the whole shipment.
Answer:
(0.089 ; 0.151)
Step-by-step explanation:
Given :
Sample size, n = 300
Number of defective items, x = 36
The confidence interval required here is that for a one sample proportion :
The confidence interval is defined thus :
Phat ± Zcritical * √[Phat(1 - phat) / n]
Zcritical at 90% = 1.645
Phat = x / n = 36 / 300 = 0.12
Hence,
C.I = 0.12 ± 1.645 * √[0.12(1 - 0.12) / 300]
C.I = 0.12 ± (1.645 * 0.0187616)
C.I = 0.12 ± 0.0308629
C.I = (0.089 ; 0.151)
A two-digit number is of the number
7
formed by reversing its digits. When the
number is increased by 2 times the sum of
its digits, it becomes 54. Find the number.
Answer:
C
Step-by-step explanation:
Find the length of AC
Answer:
377.19 (rounded off to 2dp)
Step-by-step explanation:
since its a right angled triangle, we can use tangent
tan(x) =opp/adj
tan(5) =33/AC
AC =33/tan(5)
I need help ASAP thank you
Answer:
√9 × √6
√54
√27 × √2
Step-by-step explanation:
We can obtain the answer to the question given above as illustrated below:
3√6
Recall
a√b = √(a×a×b)
Thus,
3√6 = √(3×3×6)
3√6 = √(9 × 6)
Recall
√(a × b) = √a × √b
√(9 × 6) = √9 × √6
Therefore,
3√6 = √9 × √6
Recall
√9 × √6 = √(9 × 6)
√9 × √6 = √54
Thus,
3√6 = √54
Recall
√54 = √(27 × 2)
√54 = √27 × √2
Therefore,
3√6 = √27 × √2
Therefore,
3√6 = √9 × √6 = √54 = √27 × √2
Which statement best applies to the slope of the line below?
A.
the slope is negative
B.
the slope is zero
C.
the slope is positive
D.
the line has no slope
Answer:
D
Step-by-step explanation:
fro the diagram below there line has no slope
Answer: B) The slope is zero
============================================================
Explanation:
Any horizontal line will always have a slope of 0. This is because there is no change in y (aka the rise is 0).
So we could say something like
slope = rise/run = 0/1 = 0
The run can be anything we want, and we'd still get 0 every time.
------------
Another way to see this is to pick two points from this line. Whichever points are selected, they are plugged into the slope formula
m = (y2-y1)/(x2-x1)
You'll find that the y2-y1 expression turns into 0. Why? Because y1 and y2 are the same, so they subtract to 0. It doesn't matter what x2-x1 turns into.
Instruction: Find the average rate of change for the scenario below.
A rocket is 1 mile above the earth in 30 seconds and 5 miles
above the earth in 150 seconds. What is the rockets rate of
change in miles per second?
Rate of Change
miles/second
Answer:
Step-by-step explanation:
Use the coordinates (30, 1) and (150, 5) to solve this. Time is always an x thing, while things like distance and weight and value are y things. Put them into the slope formula:
[tex]m(\frac{miles}{sec})=\frac{5-1}{150-30}=\frac{4}{120}=\frac{1}{30}[/tex] This translates to:
The rocket is ascending at a constant rate of 1 mile every 30 seconds; or, conversely, for every 30 seconds the rocket is flying, it is traveling 1 mile.
I'm stuck. Can anyone help please?
log₉(x - 7) + log₉(x - 7) = 1
2 log₉(x - 7) = 1
log₉(x - 7) = 1/2
Take the base-9 antilogarithm of both sides; in other words, make both sides powers of 9:
[tex]9^{\log_9(x-7)} = 9^{1/2}[/tex]
[tex]9^{1/2}[/tex] can also be written as √9 = 3, and [tex]b^{\log_b(a)}=a[/tex], so the equation reduces to
x - 7 = 3
Solve for x :
x = 10
Building A is 170 feet shorter than building B. The total height of the two buildings is 1520 feet. what is the height of each building?
Answer:
Step-by-step explanation:
If A is 170 less than B, than the equation for that is:
A = B - 170 (1) where the word "is" means equals and less than is subtraction.
If the total of A + B is 1520, then
A + B = 1520 (2). Sub equation (1) into equation (2):
(B - 170) + B = 1520 and
2B - 170 = 1520 and
2B = 1690 so
B = 845. Building B is 845 feet tall and Building A is
A = 845 - 170 (this is equation (1) with the height of B subbed in) so
A = 675 feet
675 + 845 should equal 1520 according to our equation. And of course it does.
Answer: 675 + 845 should equal 1520 according to our equation. And of course it does.
Find the area of the quadrilateral and round to the nearest tenth
Answer:
24
Step-by-step explanation:
(4+8)×4/2
= 12×4/2
= 24
Answered by GAUTHMATH
The probability of a customer arrival at a grocery service counter in any one second is equal to 0.4. Assume that customers arrive in a random stream, so an arrival in any one second is independent of all others. (Round your answers to four decimal places.) (a) Find the probability that the first arrival will occur during the seventh one-second interval. 0.0187 Correct: Your answer is correct. (b) Find the probability that the first arrival will not occur until at least the seventh one-second interval.
Answer:
a. approximately 0.0187
b. 0.047
Step-by-step explanation:
q = 1-p
= 1-0.4
q = 0.6
a. the probability that the first arrival will occur during seventh one-second interval
probability(7) = 0.6⁷⁻¹ x 0.4
= 0.6⁶ x 0.4
= 0.046656 x 0.4
= 0.0186624
approximately 0.0187
b. probability that the first arrival will not occur until at least the seventh one second interval
p(y≥7) = 1-p(x<7)
= 1-[(0.4)(0.6)⁰ + (0.4)(0.6)¹ +(0.4)(0.6)²+(0.4)(0.6)³+(0.4)(0.6)⁴+(0.4)(0.6)⁵]
= 1-(0.4+0.24+0.144+0.0864+0.05184+0.031104
= 1-0.95334
= 0.04667
= 0.047
The population p(t) of a culture of the bacterium Pseudomonas aeruginosa is given by ,p(t)= -1683t^2+75,000t+ 10,000 where is the time in hours since the culture was started. Determine the time the population was at its maximum. Round to the nearest hour.
Answer:
22hrs
Step-by-step explanation:
hope it is well understood?
2.5 cm in the ratio of 1:500000
Answer:
1250000cm
Step-by-step explanation:
1:500000
1x2.5 : 500000x2.5
2.5:1250000
In an experiment, the initial temperature of a solution is -5 °C. The solution is heated up at 3 °C per minute for 19 minutes and then it is cooled at 4 °C per minute for 6 minutes. Calculate the final temperature, in °C, of the solution.
Answer:
28°C
Step-by-step explanation:
First you do 3*19=57°C
-5+57= 52°C
then you do 4*6=24 °C
as its being cooled you takeaway
52-24=28°C
which lines are parallel?
Answer:
Lines 'p' and 'q' are parallel I believe!
Step-by-step explanation:
They are the only two lines relating to angles 8 and 11 of the three listed pairs.
Answer:
p and q are parallel
Step-by-step explanation:
4.Siti and Janice spent 3h 25min altogether in Shopping malls A and B. If they spent 1h 45min in Shopping mall A, how long did they spend in Shopping mall B?
Answer:
1 hour and 40 minutes
Step-by-step explanation:
→ Convert 3 hr and 25 minutes to minutes
( 3 × 60 ) + 25 = 205 minutes
→ Convert 1 hr and 45 minutes to minutes
( 1 × 60 ) + 45 = 105 minutes
→ Minus the answers from each other
205 - 105 = 100 minutes
→ Convert 100 minutes to hours and minutes
1 hour and 40 minutes
if x¹=xcosA+ysinA and y¹=xsinA-ycosA, show that (x¹)²+(y¹)²=x²+y²
Expanding each square on the left side, you have
(x cos(A) + y sin(A))² = x² cos²(A) + 2xy cos(A) sin(A) + y² sin²(A)
(x sin(A) - y cos(A))² = x² sin²(A) - 2xy sin(A) cos(A) + y² cos²(A)
so that adding them together eliminates the identical middle terms and reduces to the sum to
x² cos²(A) + y² sin²(A) + x² sin²(A) + y² cos²(A)
Collecting terms to factorize gives us
(y² + x²) sin²(A) + (x² + y²) cos²(A)
(x² + y²) (sin²(A) + cos²(A))
and sin²(A) + cos²(A) = 1 for any A, so we end up with
x² + y²
as required.
Answer please answer!!
I need the answer asap
Answer:
35 cm
Step-by-step explanation:
is the correct answer
Draw a graph of direct proportion, expressed by the formula: y=3x
Answer.
ANSWER
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