Hypothesis test for single mean.
Faced with rising fax costs, a firm issued a guideline that transmissions of 10 pages or more should be sent by 2day mail instead. Exceptions are allowed, but they want the average to be 10 or below. The firm examined 35 randomly chosen fax transmissions throughout the next year, yielding a sample mean of 14.44 with a standard deviation of 4.45 pages.
a. At the .01 level of significance, is the true mean greater than 10?
b. utilize Excel to find the righttail pvalue.
N = 35 M= 14.44, STD DEV 4.45,
H_{0} less than or equal to10
H_{1}>10
Z_{0.01}= 2.326
(1014.44)/(4.45 /sq root 35)= 0.44/0.7521= 0.5850
P (Z less than equal to  0.5850)=0.7207
10.7207= 0.2800
H_{1} alternative is accepted.
Confidence interval  mean

99%

confidence level

14.44

mean

4.45

std. dev.

35

n

2.576

z

1.938

halfwidth

16.378

upper confidence limit

12.502

lower confidence limit
