0 Question 5 v B 1/3 pts '0 99-100 8 99 (D Details Score on last try: 1 of 3 pts. See Details for more. > Next question 3 Get a similar question You can retry this question below Suppose that textbook weights are normally distributed. You measure 38 textbooks' weights, and find they have a mean weight of 53 ounces. Assume the population standard deviation is 9.9 ounces. Based on this, construct a 95% confidence interval for the true population mean textbook weight. Round answers to 2 decimal places. A 1: O K A A researcher is interested in finding a 95% confidence interval for the mean number of times per day that college students text. The study included 125 students who averaged 42.8 texts per day. The standard deviation was 21.4 texts. Round answers to 3 decimal places where possible. a. To compute the confidence interval use a ? c distribution. b. With 95% confidence the population mean number of texts per day is between and texts. c. If many groups of 125 randomly selected members are studied, then a different confidence interval would be produced from each group. About percent of these confidence intervals will contain the true population number of texts per day and about percent will not contain the true population mean number of texts per day. In a survey, 23 people were asked how much they spent on their child's last birthday gift. The results were roughly bell-shaped with a mean of $39.9 and standard deviation of $19.7. Estimate how much a typical parent would spend on their child's birthday gift (use a 99% confidence level). Give your answers to 3 decimal places. Express your answer in the format of 37: i E. $ is