A telephone exchange operator assumes that 9% of the phone calls are wrong numbers. If the operator is correct, what is the probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%

Answers

Answer 1

Answer:

0.0264 = 2.64% probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score 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 p-value, we get the probability that the value of the measure is greater than X.

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]

A telephone exchange operator assumes that 9% of the phone calls are wrong numbers.

This means that [tex]p = 0.09[/tex]

Sample of 448

This means that [tex]n = 448[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.09[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.09*0.91}{448}} = 0.0135[/tex]

What is the probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%?

More than 9% + 3% = 12 or less than 9% - 3% = 6%. Since the normal distribution is symmetric, these probabilities are the same, so we find one of them and multiply by 2.

Probability it is less than 6%

P-value of Z when X = 0.06. So

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.06 - 0.09}{0.0135}[/tex]

[tex]Z = -2.22[/tex]

[tex]Z = -2.22[/tex] has a p-value of 0.0132

2*0.0132 = 0.0264

0.0264 = 2.64% probability that the proportion of wrong numbers in a sample of 448 phone calls would differ from the population proportion by more than 3%


Related Questions

Identify the triangle, ABC, which has a 72∘ angle and a 36∘ angle.

Answers

Answer:

isosceles acute

Step-by-step explanation:

sum of angles in a triangle = 180

to find third angle, subtract 72 & 36 from 180 and you get 72

72, 36, and 72 are all less than 90 so it will be an acute triangle

It will also be isosceles bc there are 2 angles of the same measure

Find the area AND perimeter of the shaded regions below. Give your answer as a completely simplified exact value in terms of π (no approximations).

Answers

Answer:

a=40+8pi, p=4pi+4(sqrt of 29)

Step-by-step explanation:

rsm geometry class 122?

Which equation shows a slope of 3 and a y-intercept of (0,7)?
y = 7x + 3
y = −7x + 3
y = 3x
y = 3x + 7

Answers

Answer:

[tex]{ \tt{y = 3x + 7}}[/tex]

Step-by-step explanation:

General equation of a line:

[tex]{ \boxed{ \bf{y = mx + c}}}[/tex]

m is the slope, and c is the y-intercept:

m = 3, and c = 7

With a two dimensional surface, if we take (2, 1) as the center point and consider

a transformation with a rotation angle of 45◦, then point (3, 3) is transformed

into point (----)?​

Answers

Answer:

Step-by-step explanation:

Distance between (2,1) and (3,3) = √5

parametric equations for circle of radius √5, centered at (2,1):

x = √5cosθ+2

y = √5sinθ+1

At (3,3), θ = arccos(1/√5) ≅ 63.4°

After 45° transformation:

θ' = 63.4° + 45° = 108.4°

x' = √5cos(108.4°)+2 = 1.29

y' = √sin(108.4°)+1 = 3.12

(3,3) transformed to (1.29,3.12)

Question 6 plz show ALL STEPS

Answers

Step-by-step explanation:

6a. Both the x and y coordinates are negative so this means isn't must be in the Third Quadrant.

6b. The measure of this using the unt circle is

[tex] \cos(x) - \frac{1}{2} [/tex]

[tex] \sin(x) = - \frac{ \sqrt{3} }{2} [/tex]

In the unit circle, this occurs about

an angle of 240 degrees. We can find coterminal angles within the interval of 2 pi to -2 pi. Just subtract 260 from theta.( which is 240)

[tex]240 - 360 = - 120[/tex]

So the angles in the interval is

240, -120.

6c. pi/2 is the same as 90 degrees so this means that

[tex](240 + 90) = 330[/tex]

In the unit circle, we know that at 330 degrees,

[tex] \cos(330) = \frac{ \sqrt{3} }{2} [/tex]

[tex] \sin(330) = \frac{1}{2} [/tex]

So the coordinates are

(sqr root of 3/2, 1/2).

6d. pi is the same as 180 degrees so this means that

[tex](240 - 180) = 60[/tex]

In the unit circle, we know that 60 degrees,

[tex] \cos(60) = \frac{1}{2} [/tex]

[tex] \sin(60) = \frac{ \sqrt{3} }{2} [/tex]

So the coordinates are

(1/2, sqr root of 3/2)

4. Work out the area.



Answers

Answer:

90m^2

Step-by-step explanation:

image shows a trapezium,

area of trapezium = h(a+b)/2 = 9(8+12)/2 = 90

Answer:

29

12+8+9 =29

Step-by-step explanation:

additional question

add tose measure

Which of the following equations shows the linear relationship between the x and y variables shown in the table of ordered pairs? A. y = x + 5 B. y = 2x C. y = x + 6 D. y = x - 5

Answers

Answer:

The linear relationship will be B

Answer:

b

Step-by-step explanation:

Write an algebraic expression for each person’s share, if P people share 16 slices of pizza equally.

Answers

Answer:

P /16

Step-by-step explanation:

Take the total amount, P and divide by the number of people sharing, 16

P /16

Value of x
1\5(x)(1/5)=6/3(5/1)

Answers

Answer:

1/25=3/30

1250=

2501

2389

5552

Part III- Percentage Problems

1. You currently have $4,500 saved in your bank account. You have decided to use $2700.

What percentage of your savings did you use? Show all your work to justify your answer.

2. An organization raises money for students who attend Berkeley College every year.

Currently, they have raised $11,250 which represents 45% of the money they raise.

Determine the amount of money the organization will raise in total. Show all your work

to justify your answer.

Answers

The percentage of your savings that I use is 60%

This shows that the amount of money the organization will raise in total is $25,000.

1) Given

Total amount saved = $4500

Amount used = $2,700

Percentage of money used = Amount used/Total amount saved × 100%

[tex]Percentage \ of \ money \ used = \frac{2700}{4500} \times 100\\Percentage \ of \ money = \frac{27}{45} \times 100\\Percentage \ of \ money \ used = \frac{2700}{45} \\Percentage \ of \ money \ used = 60 \%[/tex]

Hence the percentage of your savings that I use is 60%

2) Let the amount of money the organization will raise in total be x

Since the 45% of the money they raise represents $11,250, hence:

[tex]45\% \ of \ x = \$11,250\\0.45x = 11,250\\x = \frac{11250}{0.45}\\ x = 25,000[/tex]

This shows that the amount of money the organization will raise in total is $25,000

Learn more on percentages here: https://brainly.com/question/18811795

ZDAC = ZBAD.
What is the length of CD?
Round to one decimal place.

Answers

Answer:

3.4

Step-by-step explanation:

The angle bisector theorem states that for a triangle that is bisected, the ratio between the two edges in each of the triangles that form are proportional to each other.

For this triangle, the bisector splits the triangle into ΔABD and ΔACD. The edges of ΔABD are BD and AB, while the edges of ΔACD are CD and AC. Therefore, we can say that BD/AB = CD/AC . Note that both parts of line that is bisected (BC) are on top, while the other edge sides are on the bottom. *

BD/AB = CD/AC

2.6/4.9 = ? / 6.5

multiply both sides by 6.5 to isolate the ?

2.6 * 6.5 / 4.9 = ? ≈ 3.4

* this can also be rearranged so that AB/BD = AC/CD, but it is vital to ensure that either both sides that are part of the larger triangle are on top or both parts of the bisected line are on top

If the average(arithmetic mean) of g and 100 is 75,what is the value of g + 100?

Answers

The value of g + 100 is 150.

Given that,

The average of g and 100 is 75.

And we have to determine the value of g + 100.

So that means

The arithmetic mean of g and 100 is 75.

So, mathematically it should be

[tex]\frac{g + 100}{2} = 75\\\\[/tex]

So, g + 100 = 150

Therefore we can conclude that the value of g + 100 is 150

Learn more about the mean here: brainly.com/question/11230531

How many more cherry pies have 60 to 89 cherries than 90 to 119 cherries?

Answers

Answer:

6 pies

Step-by-step explanation:

For 60 - 89 cherries there are 10 pies

For 90 -119 cherries there are 4 pies

10 -4 = 6

There are 6 more pies in the 60 -89 cherries category than in the 90-119 category

Solve this inequality: 4x-8>-40

Answers

Answer:

x > - 8

Step-by-step explanation:

4x - 8 > - 40

4x > - 40 + 8

4x > - 32

Divide 4 on both sides,

4x / 4 > - 32 / 4

x > - 8

Answer:

x > 12

Step-by-step explanation:

4x - 8 > 40

Add 8 to both sides

4x > 48

Divide both sides by 4

x > 12

Find the Perimeter of the figure below, composed of a rectangle and two semicircles.
Round to the nearest tenths place.
15
10
WILL GIVE BRAINLIEST

Answers

Answer:

61.42 units

Step-by-step explanation:

Perimeter = sum of all sides of surrounding the figure = circumference of a circle + 2(length of the rectangle)

Note: two semicircles = 1 full circle

Perimeter = πd + 2(L)

Where,

Diameter of the circle (d) = 10

Length of rectangle (L) = 15

Plug in the values

Perimeter = π*10 + 2(15)

Perimeter = 10π + 30

≈ 61.42 units (approximated to nearest tenths)

You are trying to get an important customer order out the door, but your boss keeps coming over to ask you about the status of this order and several other orders. He's just nervous and wants to be

Answers

it’s should be a i think

Which sequence is arithmetic?
O 2, 6, 18, 54, ...
O 3, 6, 12, 24, ...
O 11, 14, 17, 20, ...
O 7, 11, 13, 18, ...

Answers

Answer:

11, 14, 17, 20, ...

Step-by-step explanation:

An arithmetic sequence is one where each term increases by the same number every time. This is called the common difference and is always added to the previous term to get the current term. The only sequence that follows this is the third once. Every term increases by 3; therefore, it is an arithmetic sequence.

PQRS is a parallelogram of area 18 cm. if PQ = 5 cm & QR = 4 cm. calculate the lengths of corresponding heights ?​

Answers

Answer:

2cm

Step-by-step explanation:

area of parallelogram=b*h=18cm

5*4=20

length of corresponding heights=20-18

=2cm

the length of corresponding height of the parallelogram is : 2cm

Meaning of a parallelogram

A parallelogram can be defined as a simple quadrilateral that is it possesses four sides and two pairs of parallel sides.

A opposite sides of a parallelogram are equal and the opposite angles of a parallelogram are equal.

In conclusion, the length of corresponding height of the parallelogram is : 2cm

Learn more about  parallelogram : https://brainly.com/question/970600

#SPJ2

find the midpoint of the segment with the following endpoints (10,6) and (3,1)

Answers

Answer:

(6.5,3.5)

Step-by-step explanation:

To find the x coordinates of the midpoint, average the x coordinates of the endpoints

(10+3)/2 = 13/2 = 6.5

To find the y coordinates of the midpoint, average the y coordinates of the endpoints

(6+1)/2 = 7/2 = 3.5

(6.5,3.5)

A certain drug is used to treat asthma. In a clinical trial of theâ drug, 17 of 258 treated subjects experienced headachesâ (based on data from theâ manufacturer). The accompanying calculator display shows results from a test of the claim that less than 11â% of treated subjects experienced headaches. Use the normal distribution as an approximation to the binomial distribution and assume a 0.01 significance level to complete partsâ (a) throughâ (e) below. â
1-PropZTest
prop<0.11
z=â2.264337000
p=0.0117766978
p=0.0658914729
n=258
a. Is the testâ two-tailed, left-tailed, orâ right-tailed?
b. What is the best statistics?
c. What is the P-value?
d. What is the nut hypothesis and what do you conclude who det hypothesis?
Identify the null hypothesis.
A. H0: pâ 0.11.
B. H0: p=0.11.
C. H0: p<0.11.
D. H0: p>0.11.
Decide whether to reject the null hypothesis.
A. Reject the null hypothesis because theâ P-value is greater than α.
B. Fail to reject the null hypothesis because theâ P-value is less than or equal to α.
C. Reject the null hypothesis because theâ P-value is less than or equal to α.
D. Fail to reject the null hypothesis because theâ P-value is greater than α
e. What is the finalâ conclusion?
A. There is not sufficient evidence to warrant rejection of the claim that less than 11â% of treated subjects experienced headaches.
B. There is not sufficient evidence to support the claim that less than 11â% of treated subjects experienced headaches.
C. There is sufficient evidence to support the claim that less than 11â% of treated subjects experienced headaches.
D. There is sufficient evidence to warrant rejection of the claim that less than 11â% of treated subjects experienced headaches.

Answers

Solution :

a). The test is a left tailed test.

b). The sample proportion is :

[tex]$\hat p = \frac{x}{n}$[/tex]

[tex]$\hat p = \frac{17}{258}$[/tex]

  = 0.065

Determining the Z statistics using the formula :

[tex]$Z=\frac{\hat p - p}{\sqrt{\frac{p(1-p)}{n}}}$[/tex]

[tex]$Z=\frac{0.065 - 0.11}{\sqrt{\frac{0.11(1-0.11)}{258}}}$[/tex]

   = -2.31

∴ Z statistics value is -2.31

c). Using the excel function, the P-value is :

P-value = Normsdist(-2.31)

             = 0.0104441

d). The null hypothesis is [tex]$H_0: P = 0.11$[/tex]

    The level of significance is 0.01

    We fail to reject the null hypothesis as the P value is less than or equal to the significant level.

x^ 3 +x^ 2 +4x/x^ 2 +x-2
into partial
fractions​

Answers

Answer:

x + (4/ x-2) + (2/ x-1)

Step-by-step explanation:

x + (6x/ x^2 + 2x - x -2)

x + (6x/ (x + 2) X (x - 1))

(6x/ (x + 2) X (x - 1))

(A/ x+2) + (B/ x-1)

(6x/ (x + 2) X (x - 1)) = (A/ x+2) + (B/ x-1)

6x = Ax + Bx - A + 2B

6x = (A+B)x + (-A+2b)

{0 = -A+2B

{6 = A+B

(A,B) = (4, 2)

(4/ x+2) + (2/ x-1)

x + (4/ x-2) + (2/ x-1)

Select the correct answer.
Select the function that defines the given sequence.
-8, -20, -50, –125, 625,...
ОА
- 1)
f(n) = -8-()
n-
OB.
- 1)
= -8.(29)
OC f(1) = -8
f(n) = f(n − 1), for n = 2, 3, 4, ...
OD. (1) = 8
f(n) = - . 1(n − 1), for n = 2, 3, 4, ...

Answers

Answer:

Option C

Step-by-step explanation:

f(1) = -8

f(2) = -5/2×-8 = -20

f(3) = -5/2×-20 = -125

.

.

.

So option C is the answer

Answer:

C.  a1 = -8

an = an-1 * 5/2  for n >1

Step-by-step explanation:

-8, -20, -50, –125, 625,...

We need to find the common ratio

Take the second  term and divide by the first term

-20/-8 = 5/2

Take the third term and divide by the second term

-50/-20 = 5/2

The common ratio is 5/2

A geometric sequence is

an = a1 * r^(n-1)

an = -8 *(5/2)^(n-1)

We can also write a recursive formula

a1 = -8

an = an-1 * 5/2  for n >1

Hello Pls help and thanks

Answers

Answer:

c.) in the correct answer

In 2014, the population of Ohio was 11.59 million people. One-hundred years earlier the population was 5.109 million people. Using scientific notation, how much did the population grow over the hundred-year span?

Answers

The answer is the population grew over the hundred-year span by [tex]6.481*(10)^6[/tex]

Given that in 2014, the population of people in Ohio = [tex]11.59[/tex] million

Also given that One-hundred years earlier of the year 1914, the population =  [tex]5.109[/tex] million people

One-hundred years earlier in the year 2014 = 2014 [tex]- 100[/tex] years

One-hundred years earlier in the year 2014 = Year 1914

The scientific notation of the year 2014 population is [tex]11.59*(10)^6[/tex]

The scientific notation of the year 1914 population is [tex]5.109*(10)^6[/tex]

How much did the population grow over the hundred-year span?

Growth of the population from 1914-2014 = [tex]11.59*(10)^6 - 5.109*(10)^6[/tex]

Growth of the population from 1914-2014 = [tex]6.481*(10)^6[/tex]

Conclusion: The population grew over the hundred-year span by [tex]6.481*(10)^6[/tex]

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Find f′ in terms of g′

f(x)=x2g(x)

Select one:

f′(x)=2xf′(x)+2xg′(x)


f′(x)=2xg′(x)


f′(x)=2x+g′(x)


f′(x)=x2g(x)+2x2g′(x)


f′(x)=2xg(x)+x2g′(x)

Answers

f(x)g(x) if you find the derivative of two products, you get f(x)g’(x)+f’(x)g(x). Let’s say x^2 = f(x).

(x^2)(g’(x))+2x(g(x)) so it would be your last option, 2x(g(x))+x^2(g’(x))

What is the slope of the line passing through the points (6,1) and (-3,-4)?​

Answers

Answer:

5/9

Step-by-step explanation:

y2-y1/x2-x1 = 5/9

Sarah has two similar rectangular boxes. The dimensions of Box 1 are four times those of Box 2.

How many times greater is the surface area of Box 1 than the surface area of Box 2?

8

64

4

16

Answers

Answer:

16

Step-by-step explanation:

an area is always calculated by multiplying 2 dimensions.

when changing the dimensions, then the change factors for EACH dimension go into the calculation too.

therefore, when both dimensions of an area are enlarged 4 times, then the area is enlarged 4×4 = 16 times.

this just propagates to the whole surface area of an object, as each individual area of the overall surface area is enlarged by the same factor. and so, the sum of all the individual areas (= altogether the surface area of the object) is also enlarged in total by the same factor.

just think

16×a + 16×b + 16×c ... = 16×(a+b+c+...)

and you understand why.

I need help completing this problem ASAP

Answers

Answer:

D. [tex]3x\sqrt{2x}[/tex]

Step-by-step explanation:

The problem gives on the following equation:

[tex]\sqrt{32x^3}+-\sqrt{16x^3}+4\sqrt{x^3}-2\sqrt{x^3}[/tex]

Alongside the information that ([tex]x\geq0[/tex]).

One must bear in mind that the operation ([tex]\sqrt[/tex]) indicates that one has to find the number that when multiplied by itself will yield the number underneath the radical. The easiest way to find such a number is to factor the term underneath the radical. Rewrite the terms under the radical as the product of prime numbers,

[tex]\sqrt{2*2*2*2*2*x*x*x}-\sqrt{2*2*2*2*x*x*x}+4\sqrt{x*x*x}-\sqrt{2*x*x*x}[/tex]

Now remove the duplicate factors from underneath the radical,

[tex]2*2*x\sqrt{2x}-2*2*x\sqrt{x}+4x\sqrt{x}-2x\sqrt{x}[/tex]

Simplify,

[tex]4x\sqrt{2x}-4x\sqrt{x}+4x\sqrt{x}-x\sqrt{2x}[/tex]

[tex]3x\sqrt{2x}[/tex]

Janet invests a sum of EUR in an account that offers 3.5% simple interest. After ten years her investment is worth 7425 EUR. How much did she invest?

Answers

We need to find the amount of money Janet invested in 10 years to yield 7425 EUR

She invested EUR 21,214.29

Simple interest = P × R × T

Where,

P = principal = ?

R = interest rate = 3.5% = 0.035

T = Time = 10 years

Simple interest = 7425 EUR

Simple interest = P × R × T

7425 = p × 0.035 × 10

7425 = p × 0.35

7425 = 0.35p

Divide both sides by 0.35

P = 7425 / 0.35

= 21,214.285714285

Approximately,

P = EUR 21,214.29

https://brainly.com/question/10936433

factorise m^2 - 12 m + 24

Answers

Answer:

(m-6+2root3)(m-6-2root3)

Step-by-step explanation:

m^2 - 12m +36 -12

= (m-6)^2 - 12

= (m-6+2root3)(m-6-2root3)[root 12 = 2root3]

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