Question
Can you answer this question please, it's also asking *Based on your calculations from parts (a) and (b), is it likely that the increase in the average ER wait time is due to change alone?*
A hospital administrator hoping to improve wait times decides to estimate the average emergency room waiting time at her hospital. She collects a simple random sample of 84 patients and determines the time (in minutes) between when they checked in to the ER until they were first seen by a doctor. The average time is 137 5 minutes and the standard a is 39 minutes The administrator is being criticized by the hospital's CEO on the basis that the wat times in the ER have increased greatly from the previous year's average of 127 minutes. However, the administrator believes that the increase is probably just due to chance.. (a) Calculate the 99% confidence interval for the average wait time. (b) Perform a hypothesis test using the hypotheses (HD -127; Ha: 27) and a significance level a 0.01. os
Explanation / Answer
alpha / 2 = 1 -0.99/2 = 0.005
Z = 2.57
I: xbar +/- Z * SD / srqt n
I. 137.5 +/- 2.57 * 39 / srqt 64
137.5 +/- 12.53
124.97 < miu < 150.03
b)
Z = ( 137.5 - 127) / ( 39 / srqt 64 )
Z = 2.15
p value : 0.0158
since p value is greater than alpha / 2 we fail to rejec t ho
conclsuion
there is no significance level to conclude that mean is different from 27