based on the data below for a 25 day hospital stay:
medical service provided 9
mean of medical services provided 11.11
standard deviation 8.29
surgical services provided 16
mean of surgical services provided 7.19
standard deviation 3.1
is there any difference in duration of hospital stay based on what type of service the patient
received.............thank you!
Z = (mean1 - mean2)/standard error (SE) of difference between means
SEdiff = √(SEmean1^2 + SEmean2^2)
SEm = SD/√n
If only one SD is provided, you can use just that to determine SEdiff.
Find table in the back of your statistics text labeled something like "areas under normal distribution" to find the proportion/probability related to the Z score. How does it compare with your level of significance?