1/4[3×8]+2×(-12) help

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

Find the value of the cosine for angle a

Need asap i will give brainliest and 98 points classify each pair of numbered angles corresponding, alternate interior, alternate exterior or none o these