Question

6. Rolls of paper are acceptable for making bags for grocery stores if the mean breaking strength is more than 40 psi. A manufacturer has proposed a process to manufacture grocery bags from recycled paper. A test of 25 paper samples from the proposed process has a mean breaking strength of 40.93 psi and a standard deviation of 2.25 psi. Is there sufficient evidence to conclude the new process is suitable for manufacturing grocery bags. Use a=.05.

Answer 1

Solution :

This is the right tailed test .

The null and alternative hypothesis is ,

H₀ :   = 40

H_a :    40

= 40.93

= 40

s = 2.25

n = 25

df = n - 1 = 25 - 1 = 24

Test statistic = t

= ( - ) / s / n

= (40.93 - 40) / 2.25 / 25

= 2.07

Test statistic = 2.07

P-value = 0.0247

= 0.05

P-value <

Reject the null hypothesis .

There is sufficient evidence to conclude the new process is suitable for manufacturing grocery bags .