Question

A manufacturer of chocolate chips would like to know whether its bag filling machine works correctly at the 432 gram setting. It is believed that the machine is underfilling the bags. A 29 bag sample had a mean of 425 grams with a standard deviation of 26. Assume the population is normally distributed. A level of significance of 0.02 will be used. Find the P-value of the test statistic. You may write the P-value as a range using interval notation, or as a decimal value rounded to four decimal places.

Answer 1

Solution :

= 432

=425

S =26

n = 29

This is the two tailed test .

The null and alternative hypothesis is ,

H0 :    = 432

Ha :     432

Test statistic =t

= ( - ) / S / n

= (425-432) / 26 / 29

= -1.450

Test statistic = t =-1.450  

P-value =0.1582

= 0.02  

P-value >

0.1582 >0.02

Do not reject the null hypothesis .

There is insufficient evidence to suggest that