840 students attend Northfield middle school. 65%of students earned a perfect attendance award. How many students didn't earn th
1 answer:
You might be interested in
Answer:
Step-by-step explanation:
Sample proportion p is the proportion of favourable numbers to total number in the sample
By central limit theorem and also approximation of binomial to normal , we have sample proportion for large number of samples will be normal
with mean = sample proportion
and std deviation =
Thus we find standard deviation of proportion sample is inversely proportional to the square of the sample size n.
It follows automatically that as sample size increases std deviation decreases.
Here from 80 sample size was made to 200
So std deviation would decrease automatically