Please help me with this!!

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 is the correct excel formula for the 80th percentile of a distribution that is n(475, 33)? =norm.dist(80,475,33,1) =norm.inv(0.80,475,33) =norm.s.inv((80-475)/33)?

Quadrilateral wxyz is on a coordinate plane. segment yz is on the line x+y=7 and segment xw is on the line x+y=3. which statement proves how segments yz and xw are related