Question

The average college student goes through 500 disposable cups in a yeat. To raise environmental awareness, a student group at a large university volunteered to help count how many cups were used by students on their campus. A random sample of 50 student's results found that they used a mean of 476 cups with a standard deviation of 42 cups. At the 0.01 level of significance, is there sufficient evidence to conclude that the mean differs from 500? USE THE 5 STEP RESPONSE AS OUTLINED IN THE BOOK ON PAGE 413. use the z score method. (example 8-3)

Answer 1

Solution :

This is the two tailed test .

The null and alternative hypothesis is ,

H₀ :   = 500

H_a :    500

= 476

= 500

= 42

n = 50

Test statistic = z

= ( - ) / / n

= (476 - 500) / 42 / 50

= -4.04

Test statistic = -4.04

P(z < -4.04) = 0

P-value = 0 * 2 = 0

= 0.01

P-value <

Reject the null hypothesis .

There is sufficient evidence to conclude that the mean differs from 500 .