Question

Do we have evidence to suggest that the true mean weight for all 36 oz boxes of cereal is different from 36 oz? A random sample of 30 boxes had mean of 38.2 oz with a standard deviation of 5.6 oz. What is the p-value?

Question 6 options:

	about 0.98
	about 0.02
	about 0.06
	about 0.04

Answer 1

solution

this is the two tailed test .  

The null and alternative hypothesis is ,

H0 :   = 36

Ha :     36

Test statistic = z

= ( - ) / / n

= (38.02- 36) / 5.6 / 30

= 2.02/1.02242

Z=1.98

P(z >1.98 ) = 1 - P(z <1.98 ) = 1-0.9761=0.02 ( using z table )

P-value = 0.02