Basic Statistics
posted by mike on .
A population of 200 voters contains 52 Republicans, 128 Democrats, and 20 independents and members of other parties. A simple random sample of 20 voters will be drawn from this population. The expected number of Republicans in the sample is ______ ?
The standard error of the number of Republicans in the sample is _____ ?

Q1. A population has a mean of ยต = 80 with σ = 20.
a. If a single score is randomly selected from this population, how much distance, on average, should you find between the score and the population mean?
b. If a sample of n = 4 scores is randomly selected from this population, how much distance, on average, should you find between the sample mean and the population mean?
c. What is the probability that sample mean will be less than 70 for a sample of 16 scores?