What does the term expected count mean and how is it calculated

33% of college students say they use credit cards because of the rewards program. you randomly select 10 college students and ask each to name the reason he or she uses credit cards. find the probability that the number of college students who say they use credit cards because of the rewards program is (a) exactly two, (b) more than two, and (c) between two and five inclusive. if convenient, use technology to find the probabilities.

Write the fraction or mixed number and the decimal shown by the model

The standard deviation for a set of data is 5.5. the mean is 265. what is the margin of error?