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The mean age when smokers first start is 13 years old with a population standard deviation of 2 years. A researcher thinks that smoking age has significantly changed since the invention of ENDS-electronic nicotine delivery systems. A survey of smokers of this generation was done to see if the mean age has changed. The sample of 31 smokers found that their mean starting age was 12.2 years old. Do the data support the claim at the 10% significance level? What are the correct hypotheses? Ho: Select an answer v ? years H1: Select an answer v ? years Based on the hypotheses, find the following: Test Statistic z = (Give answer to at least 4 decimal places) P-value = (Give answer to at least 4 decimal places) Based on the above we choose to Select an answer The correct summary would be: Select an answer that the claim that the mean age smokers first start is different than 13. The lengths of pregnancies in a small rural village are normally distributed with a mean of 270 days and a standard deviation of 16days. In what range would you expect to find the middle 98% of most pregnancies? Between and If you were to draw samples of size 60 from this population, in what range would you expect to find the middle 98% of most averages for the lengths of pregnancies in the sample? Between and Enter your answers as numbers. Your answers should be accurate to 1 decimal places. 43.5 You must estimate the mean temperature (in degrees Fahrenheit) with the following sample temperatures: 47.5 59.2 69 .8 51.9 66.3 Find the 80% confidence interval. Enter your answer as an open-interval (i.e., parentheses) accurate to two decimal places (because the sample data are reported accurate to one decimal place). 80% C.I. = Answer should be obtained without any preliminary rounding. Out of 300 people sampled, 99 preferred Candidate A. Based on this, estimate what proportion of the voting population (7) prefers Candidate A. Use a 90% confidence level, and give your answers as decimals, to three places.