Press the PS button on you X Course Hero * | Z-score Calculator * Interact ALEK'S Homework Link * |+ www.awa.aleks.com/alekscg//)/IsLexe/To_u-IgNslkr78P3, H-li-WSp540wnog8To#4545fmgWG31RYRVbH2/QdHock4718#HDX105RsptEfnAXU4cq HW: 8.1 Confidence Intervals for a Population Mean.-. Question 9 of 9 (1 point) | Question Attempt 3 of 3 199 169 385 329 269 149 135 249 309 299 Sand date to Excel Assume the population standard deviation is a = $2. Perform the following. Part 1 of 3 (a] Explain why it is necessary to check whether the population is approximately normal before constructing a confidence Interval. It is necessary to check whether the population is approximately normal because the sample size is less than or equal to 30 Part 2 of 3 (b) Following is a dotplot of these data. Is it reasonable to assume that the population Is approximately normal? . . . w reasonable to assume that the population is approximately normal. Part: 2 / 3 Part 3 of J (c) If appropriate, construct a 959% confidence Interval for the mean price for all phones of this type being sold on the Internet in 2013, Round your intermediate step to three decimal places. Round your answer to one decimal place. A 95% confidence interval for the mean price for all phones of this type being sold on the Internet in 2013 Is X Skip Part Check Save For Later O