Amanufacturer of banana chips would like to know whether its bag filling machine works correctly at the 447.0 gram setting. it is believed that the machine is underfilling the bags. a 41 bag sample had a mean of 443.0 grams. a level of significance of 0.02 will be used. determine the decision rule. assume the standard deviation is known to be 21.0.

A manufacturer of banana chips would like to know whether its bag filling machine works correctly at the 447.0 gram setting.

So, Null hypothesis :

It is believed that the machine is under filling the bags

So, Alternate hypothesis :

n = 41

Population standard deviation =

x = 443

We will use z test since n > 30 and we are given the population standard deviation.

Formula :

Use z table to find p value

p value = 0.1131

α = 0.02

p value > α

So, we fail to reject null hypothesis.

So, its bag filling machine works correctly at the 447.0 gram setting.