O CONFIDENCE INTERVALS AND HYPOTHESIS TESTING Anna Confidence interval for the population mean: Use of the t... 0/5 Espanol A toy manufacturer wants to see how long, on average, a new toy captures children's attention. He tests 13 children selected at random and finds that their mean attention span is 30 minutes with a standard deviation of 4 minutes. If we assume that attention spans are normally distributed, find a 95% confidence interval for the mean attention span of children playing with this new toy. Then find the lower limit and upper limit of the 95% confidence interval. Carry your intermediate computations to at least three decimal places. Round your answers to one decimal place. (If necessary, consult a list of formulas.) D Lower limit: X 5 ? Upper limit: As K