The government reported that the mean for daily coffee consu

The government reported that the mean for daily coffee consumption for adults is 1.65 cups. A sample of 38 adults from Arizona consumed mean of 1.84 cups with standard deviation of .85 cups. At 0.05 level of significance, could adults from Arizona be considered significantly different from US adults?

Solution

n = 38

SD = 0.85

Null Hypothesis H0: Mu = 1.65

Alternate Hypothesis Ha : Mu != 1.65

z = ( 1.84 - 1.65) / (0.85 / sqrt(38))

= 1.38

This ia a two tailed test,

Therefore,

P-value= 2* (1- 0.9162) = 0.1676

Since , P >0.05

Failed to reject null hypothesis i.e insufficient evidence to say that adults from Arizona be considered significantly different from US adults.