Explore BrainMass

Confidence interval for mean and proportion

Let's assume that the family size factor for the class was collected from randomly selected students taking Elements of Statistics from FHSU?even though we know the data was not randomly collected from such students.

a. First, determine from this sample data the proportion (percentage) of students from families of size 4 or greater.
b. Explain why it would be wrong to use the proportion calculated above, even if the data came from a random sample, as the proportion value for ALL FHSU Element of Statistics students from families of size 4 or greater.

c. Next, based upon a 95% level of confidence, determine the margin of error in estimating the true population proportion of families of size 4 or greater from the sample's proportion. Give this margin of error value below.

d. Next use your margin of error value to produce the 95% confidence interval for the population proportion as predicted from the sample results. State this interval below within an interpretive sentence.


Solution Summary

This solution gives the step by step method for computing confidence interval for mean and proportion.