Restaurant etiquette dictates that you should have a 15 %

A research group needs to determine a 90% confidence interval for the mean repair cost for all car insurance small claims. From

lutik1710 [3]

Answer:

a) $z = 1.645$

b) The should sample at least 293 small claims.

Step-by-step explanation:

We have that to find our $\alpha$ level, that is the subtraction of 1 by the confidence interval divided by 2. So:

$\alpha = \frac{1-0.9}{2} = 0.05$

Now, we have to find z in the Ztable as such z has a pvalue of $1-\alpha$ .

So it is z with a pvalue of $1-0.05 = 0.95$ , so $z = 1.645$ , which means that the answer of question a is z = 1.645.

Now, find the margin of error M as such

$M = z*\frac{\sigma}{\sqrt{n}}$

In which $\sigma$ is the standard deviation of the population and n is the size of the sample.

(b) If the group wants their estimate to have a maximum error of $12, how many small claims should they sample?

They should sample at least n small claims, in which n is found when

$M = 12, \sigma = 124.88$ . So

$M = z*\frac{\sigma}{\sqrt{n}}$

$12 = 1.645*\frac{124.88}{\sqrt{n}}$

$12\sqrt{n} = 205.43$

$\sqrt{n} = \frac{205.43}{12}$

$\sqrt{n} = 17.12$

$\sqrt{n}^{2} = (17.12)^{2}$

$n = 293$

The should sample at least 293 small claims.

8 0

3 years ago

Which statement is true regarding the graphed functions?

Vladimir79 [104]

let's analyze each case to determine the solution

case 1) f(0) = 2 and g(–2) = 0

For x=0-----> find the value of f(0) in the graph-----> f(0)=4

For x=-2-----> find the value of g(-2) in the graph-----> g(-2)=0

therefore

the statement of the case 1) is false

case 2) f(0) = 4 and g(–2) = 4

For x=0-----> find the value of f(0) in the graph-----> f(0)=4

For x=-2-----> find the value of g(-2) in the graph-----> g(-2)=0

therefore

the statement of the case 2) is false

case 3) f(2) = 0 and g(–2) = 0

For x=2-----> find the value of f(2) in the graph-----> f(2)=0

For x=-2-----> find the value of g(-2) in the graph-----> g(-2)=0

therefore

the statement of the case 3) is true

case 4) f(–2) = 0 and g(–2) = 0

For x=-2-----> find the value of f(-2) in the graph-----> f(-2) is greater than 12

For x=-2-----> find the value of g(-2) in the graph-----> g(-2)=0

therefore

the statement of the case 4) is false

therefore

the answer is

f(2) = 0 and g(–2) = 0-------> this statement is true

6 0

3 years ago

Read 2 more answers

Can someone help me out with this problem ?

expeople1 [14]

I believe that’s it .... i’m so so sorry if it’s not

8 0

3 years ago

Problem page isabel runs 7 miles in 50 minutes. at the same rate, how many miles would she run in 75 minutes?

sammy [17]

if isabel runs 7 miles in 50 minutes, then you know she runs 7/50 miles in one minute, right? So multiply that by the number of minutes she did run, and you can find the distance:

 7
------ x 75 =
50

525
------
50

 If you plug that fraction into your calculator, you get 10.5, so 10 and a half miles.

8 0

3 years ago

Find all the zeros for each function P(x)=x^4-4x^3-x^2+20x-20

ivanzaharov [21]

Answer:

The zeros of the given polynomial function are

2,2, $\pm\sqrt{5}$