sorry...it should say
x, s, n
x=mean
s=standard deviation
n=number of patients
Suppose we divide the patients according to whether or not they received antibiotics, and calculate the
mean and standard deviation for each of the two subsamples:
answers:
x, s, n x sd n
Antibiotics 11.57, 8.81, 7
No antibiotics 7.44, 3.70, 18
interpretation:
It appears that antibiotic users stay longer in the hospital.
help,
I understand how to get the answers given the set of data using the formula, but i don't understand the interpretation. Thank you
2 answers
Is this what you have done?
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 that relate to your level of significance? If the probability is smaller and your mean is for length of hospital stays, the interpretation is correct.
However, I do not see any control for severity of the illness. More severe disorders would probably require antibiotics and longer stays.
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 that relate to your level of significance? If the probability is smaller and your mean is for length of hospital stays, the interpretation is correct.
However, I do not see any control for severity of the illness. More severe disorders would probably require antibiotics and longer stays.