I need help with this question thanks!

4) a) The mean amount of time a random sample of 52 Americans 16 and older spent watching television each day is 2.8 hours and it is known the population standard deviation is 0.65 hour. Construct a 98% confidence interval for the population mean amount of time Americans 16 or older watch television. Interpret your result. b) If in the above scenario, a claim is made that the population mean number of hours Americans age 16 and older watch television is 2.5 hours per day. Would this claim be valid or invalid, based on the results in part (a)