Question

A recent national survey found that high school students watched an average (mean) of 7.2 DVDs per month with a population standard deviation of 0.90 hour. The distribution of DVDs watched per month follows the normal distribution. A random sample of 35 college students revealed that the mean number of DVDs watched last month was 6.20. At the 0.05 significance level, can we conclude that college students watch fewer DVDs a month than high school students?

e.	What is the p-value? (Round your answer to 4 decimal places.)

p-value

Answer 1

Solution :

Given that,

Population mean = = 6.20

Sample mean = = 7.2

Population standard deviation = = 0.90

Sample size = n = 35

Level of significance = = 0.05

This is a two tailed test.

The null and alternative hypothesis is,

Ho: 7.2

Ha: 7.2

The test statistics,

Z =( - )/ (/n)

= ( 7.2 - 6.20 ) / ( 0.90 / 35 )

= 6.57

p-value = 2 * P(Z > z)

= 2* ( 1 - P(Z < 6.57 ))

= 2* ( 1 - 1 )

= 0.0000

The p-value is = 0