Purina produces dog food sold in 40-lb. bags. When the filling process is working properly, the standard deviation for the bag weights is 1.4 ounces. The following data represent a random sample of 30 bags from this process. The data can also be found in the Excel file Purina dog food.xlsx.

40 38 42 41 39 42 41 43 41 37 41 39 39 37 40 39 43 41 39 41 42 37 39 40 38 38 37 38 41 39

a. Using a = 0.05, determine if the filling process is performing satisfactorily.

b. Verify your results using PHStat.

c. Interpret the p-value obtained from the software.

AppendixLO1