Question

9. A company that produces snack foods uses a machine to package 454 grams bags of potato hips. A random sample of 49 bags of potato chips has a mean of 450 grams and standard deviation of 8.48 grams. Perform a hypothesis test at the 5% significance level to determine if the machine is working properly

Answer 1

Solution:

This is a two tailed test.

The null and alternative hypothesis is,

Ho: 454

Ha: 454

The test statistics,

t =( - )/ (s /n)

= ( 450 - 454 ) / ( 8.48 / 49 )

= -3.743

P-value = 0.0005

The p-value is p = 0.0005 < 0.05, it is concluded that the null hypothesis is rejected.

There is sufficient evidence to conclude that the machine is working properly, at 0.05 level of significance.