One company claims that their new developed battery lasts longer than 48 hours under specific conditions, One random sample is drawn and showing below. 55, 41, 53, 52, 48, 50, 51. Assuming the hours of battery follows normal distribution. 1(7). Implement a hypothesis test to test if the company's claim is true. Solve by reject regionl method, Let significance level a = 0.05, 2(1)- Calculate 98% confidence interval for the true mean hours of the battery