The ages of a group of 139 randomly selected adult females have a standard deviation of 16.6 years. assume that the ages of female statistics students have less variation than ages of females in the general population, so let sigmaequals16.6 years for the sample size calculation. how many female statistics student ages must be obtained in order to estimate the mean age of all female statistics students? assume that we want 90% confidence that the sample mean is within one-half year of the population mean. does it seem reasonable to assume that the ages of female statistics students have less variation than ages of females in the general population?

Quick! a survey of 57 customers was taken at a bookstore regarding the types of books purchased. the survey found that 33 customers purchased mysteries, 25 purchased science fiction, 18 purchased romance novels, 12 purchased mysteries and science fiction, 9 purchased mysteries and romance novels, 6 purchased science fiction and romance novels, and 2 purchased all three types of books. a) how many of the customers surveyed purchased only mysteries? b) how many purchased mysteries and science fiction, but not romance novels? c) how many purchased mysteries or science fiction? d) how many purchased mysteries or science fiction, but not romance novels? e) how many purchased exactly two types of books?

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5

Bc and bd are opposite rays. all of the following are true except a)a,b,c,d are collinear b)a,b,c,d are coplanar c)bc=bd d)b is between c and d