Bonjour,pouvez vous m’aider ;)

A class survey in a large class for first-year college students asked, “About how many minutes do you study on a typical weeknig

Anika [276]

Answer: (110.22, 125.78)

Step-by-step explanation:

The confidence interval for the population mean is given by :-

$\mu\ \pm z_{\alpha/2}\times\dfrac{\sigma}{\sqrt{n}}$

Given : Sample size = 463

$\mu=118\text{ minutes}$

$\sigma=65\text{ minutes}$

Significance level : $\alpha=1-0.99=0.01$

Critical value : $z_{\alpha/2}=z_{0.005}=\pm2.576$

We assume that the population is normally distributed.

Now, the 90% confidence interval for the population mean will be :-

$118\ \pm\ 2.576\times\dfrac{65}{\sqrt{463}} \\\\\approx118\pm7.78=(118-7.78\ ,\ 118+7.78)=(110.22,\ 125.78)$

Hence, 99% confidence interval for the mean study time of all first-year students = (110.22, 125.78)

3 0

3 years ago

mrs. robinson bought a novel at bookstore on sale for 20% off its regular price of $ 29.99.mr. chang bougth the same novel at a

agasfer [191]

29.99-20%= 23.99
25.00-10%= 22.50 so, Mr.chang got the better deal ( but not by much.)

4 0

3 years ago

Read 2 more answers

Next telephone company charges $0.07 Per minute for a weekend calls and $0.09 Per minute for calls made on weekdays. This month

mr Goodwill [35]

You should suck a long rod and the answer is around 50 minutes

8 0

3 years ago

Suppose that G(X) = F(x+ 9). Which statement best compares the graph of

coldgirl [10]

Answer: Option D

Step-by-step explanation:

By definition if we have a function F (x) and perform a transformation of the form

$G (x) = F (x + c)$

Then it is true that:

If c is negative the graph of G(x) will be equal to the graph of F(x) displaced horizontally c units to the right

If c is positive, the graph of G(x) will be equal to the graph of F(x) displaced horizontally c units to the left.

Note that in this case the transformation is:

$G (x) = F (x + 9)$

Then $c = 9$ and $c> 0$

Therefore the graph of G(x) will be equal to the graph of F(x) displaced horizontally <em>9 units to the left</em>

The answer is the option D.

5 0

3 years ago

Read 2 more answers

Can you guys help me please!!

ella [17]

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1.C

2.C

3.D

4.D

5.D

6.A

7.C

8.B

9.A

10.C

11.A

12.B

13.D

14.C

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7 0

3 years ago