In: Statistics and Probability
5) After implementing a new strategy to improve services for patients, the Emergency Department of a hospital claims customers spend fewer than 20 minutes on average to see a physician. A randomly selected sample of 132 patients shows the average wait time of 18.2 minutes. Test the Emergency Department's claim at the 10% level of significance, assuming the standard deviation of wait time for all patients in that hospital is 2.3 minutes
Answer:-
Given That:-
5) After implementing a new strategy to improve services for patients, the Emergency Department of a hospital claims customers spend fewer than 20 minutes on average to see a physician. A randomly selected sample of 132 patients shows the average wait time of 18.2 minutes. Test the Emergency Department's claim at the 10% level of significance, assuming the standard deviation of wait time for all patients in that hospital is 2.3 minutes
Here, we have to use one sample z test for the population mean.
The null and alternative hypotheses are given as below:
Null hypothesis: : Customers spend 20 minutes on average to see a physician.
Alternative hypothesis: : Customers spend fewer than 20 minutes on average to see a physician.
versus
This is a lower tailed test.
The test statistic formula is given as below:
From given data, we have
Critical value
(by using z-table or excel)
Z = -8.9915
P-value = 0.0000
(by using Z-table)
P-value
So, we reject the null hypothesis
There is sufficient evidence to conclude that Customers spend fewer than 20 minutes on average to see a physician.