this is the question

A company producing electric cars advertise a reach of 500 km for a certain model On suspicion that the company was exaggerating the reach in their advertising, an independent test was done on six different cars. The test gave the following reach in km We assume that the reach of electric cars follows a normal distribution. 465, 460, 490, 480, 470, 485 a) What are the sample mean and sample standard deviation? b) Estimate a 95 %two taed condence interval for the population mean c) Use a t-test to determine whether there is reason to believe that the company has been exaggerating the car's reach (even though the sample is small). Test at the 5 % level (1) Show how you conclude using a diagram