<u>Answer</u>: No, we do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.

Step-by-step explanation:

As per given , we have

$H_0: \mu=9.4\\\\H_a:\mu\neq9.4$ , since $H_0$ is two-tailed so , the test is a two tail test.

Since population standard deviation is unknown, so we use t-test.

Critical value (two-tailed) for significance level of 0.01= $t_{n-1,\alpha/2}=t_{49, 0.005}\pm2.609228$

For n =50 , $\overline{x}=8.6$ and s= 4.8

Test statistic : $t=\dfrac{\overline{x}-\mu}{\dfrac{s}{\sqrt{n}}}$

$t=\dfrac{8.6-9.4}{\dfrac{4.8}{\sqrt{50}}}\approx-1.18$

Since test statistic value (-1.18) lies in critical interval (-2.609228, 2.609228), it means the null hypothesis is failed to reject.

We do not have sufficient evidence to conclude that the mean call duration, µ, is different from the 2010 mean of 9.4 minutes.

4 0

3 years ago

8 1/4=d÷ 2/12<br><br>plz help assignment due in 30 min!

pogonyaev

Answer:

exact form: d=99/2

decimal form: 49.5

mixed number form: 49 1/2

Step-by-step explanation:

sorry for the hold up

7 0

3 years ago