What is c•c•c•c in algebra

Asimple random sample of size nequals14 is drawn from a population that is normally distributed. the sample mean is found to be x overbar equals 70 and the sample standard deviation is found to be sequals13. construct a 90% confidence interval about the population mean

Which term best describes the association between variables a and b

Acircle has a circumference of 28.36 units what is the diameter of the circle