tons (12 marks) We wish to compare the lifespans of smartphones produced by two companies, From comparty Putre solvent Is smartphones at random, From company B, we select 10 smartphones at random, We find the average lifespan for company A's phones is 148 weeks with a standard deviation of 83 weeks, and company phones have an average lifespan of 153 weeks with a standard deviation of 5.1 weeks. Let Us. by be the treat lifespan of smartphones produced by company A, B (respectively). Assume that the lifespans are independent and normally distributed. YOU DO NOT NEED TO CHECK THE MODEL CONDITIONS. a. Do the data provide sufficient evidence that the mean lifespans of the smartphones produced try the two companies are the same? Test using a = 0.05. State the hypotheses, give the test statistic value, the p-value, and state your conclusion. (8 marks) b. Compute a 90% confidence interval for 1 - H2. (4 marks)