Two companies that manufacture batteries for electronics products have submitted their products to an independent testing agency. The agency tested 200 of each company’s batteries and recorded the lengths of time the batteries lasted before failure. The following results were determined:

Company A Company B x = 41.5 hours x = 39.0 hours s = 3.6 s = 5.0 Based on these data, determine the 95% confidence interval to estimate the difference in average life of the batteries for the two companies. Do these data indicate that one company’s batteries will outlast the other company’s batteries on average? Explain.