<h2><u>Answer with explanation</u>:</h2>
Let be the population mean.
As per given , we have
Since the alternative hypothesis is right-tailed , so the test is a right-tailed test.
Also, population standard deviation is given , so we perform one-tailed z-test.
Test statistic :
, where = Population mean
= Population standard deviation
n= sample size
= Sample mean
For n= 18 , ,
,
, we have
P-value (for right tailed test): P(z>2.12) = 1-P(z≤ 2.12) [∵ P(Z>z)=1-P(Z≤z)]\
=1- 0.0340=0.9660
Decision : Since P-value(0.9660) > Significance level (0.01), it means we are failed to reject the null hypothesis.
[We reject null hypothesis if p-value is larger than the significance level . ]
Conclusion : We do not have sufficient evidence to show that the goal is not being met at α = .01 .