In: Statistics and Probability
The post anesthesia care area (recovery room) at St. Luke's Hospital in Maumee, Ohio, was recently enlarged. The hope was that with the enlargement the mean number of patients per day would be more than 25. A random sample of 15 days revealed the following numbers of patients.
25 |
, 27, |
25, |
26, |
25, |
28, |
28, |
27, |
24, |
26, |
25, |
29, |
25, |
27, |
24 |
At the .01 significance level, can we conclude that the mean number of patients per day is more than 25?
Solution:
x | x2 |
25 | 625 |
27 | 729 |
25 | 625 |
26 | 676 |
25 | 625 |
28 | 784 |
28 | 784 |
27 | 729 |
24 | 576 |
26 | 676 |
25 | 625 |
29 | 841 |
25 | 625 |
27 | 729 |
24 | 576 |
∑x=391 | ∑x2=10225 |
Mean ˉx=∑xn
=25+27+25+26+25+28+28+27+24+26+25+29+25+27+24/15
=391/15
=26.0667
Sample Standard deviation S=√∑x2-(∑x)2nn-1
=√10225-(391)21514
=√10225-10192.066714
=√32.933314
=√2.3524
=1.5337
This is the right tailed test .
The null and alternative hypothesis is ,
H0 : = 25
Ha : > 25
Test statistic = t
= ( - ) / S / n
= (26.07 - 25) / 1.53 / 15
= 2.709
Test statistic = t = 2.709
P-value =0.0085
= 0.01
P-value <
0.0085 < 0.01
Reject the null hypothesis .
There is sufficient evidence to suggest that