STAT 1000Q Lecture 15: Stats Notes 15

• School: UConn
• Department: Statistics
• Course: STAT 1000Q
• Professor: Robert Apruzese

Document Summary

Statistic notes 1000q- lecture #15-cis for population proportions. Fraction of a population that has a characteristic of interest. Example: portion of adults that smoke cigarettes. Set point in the random sample of n. P hat = x / n = our estimate for p. Example: pop= students enrolled in stat 1000. True pop portion: total freshmen/total pop = 199/374. If we don"t know, we take a sample to estimate. Sample size (n)= 50 to estimate p. Each sample is random, so each value of p hat is random. Possible values of p hat: 0/50, 1/50, 2/50 49/50, 50/50. Each of these numbers have their own distribution called the sampling distribution of p hat for n=50. Properties of the sampling distributions of p hat. Has a mean of all p hat values. Mean of sample prop= mean pop prop. Has sd of all values of p hat. Sample sdp-hat = (p-hat x q-hat) / n.