$56 for 25 gallons or $30.05 for 15 gallons

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

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)

What is the solution for 6 - 7/8? explain the steps.