Answer Happy

Item 3. Average Hours of Student Sleep on a School Night Number 140 of counties 120 100 80 60 40 20 0 10 12 Average hours of sleep for individual high school students on a school night Note: These data come from a random some generated by the Census of School Random Sampler dotta rool www.amstatisensatschool/RandomSensiteExportacom The histogram above, "Average Hours for Student Sleep on a School Night," is derived from a random sample of 441 high school students. The histogram is approximately bell-shaped and fairly symmetric. Its mean is 7.2 hours and its standard deviation is 1.5 hours. We will assume this model applies to all high school students, so we will use u = 7.2 and o=1.5. This information will be used for the rest if the problems in your project.

Question 8 3 pts Use your work from the previous 2 problems using the EMPIRICAL RULE (NOT your calculator's Distribution tools) to answer the following three questions. Note that you will be giving your answers as PERCENTAGES, so be sure to correctly convert from decimal to percent, and to include your % sign in your answer. Given exact values only: do not round. About what percent of high school students would you predict sleep between 5.7 and 8.7 hours on school nights? About what percent of high school students would you predict sleep more than 8.7 hours on school nights? Some students reported that they slept very little each night. Based on the normal model, about what percentage of all students would you estimate sleep less than 2.7 hours a night?

Question 9 4 pts According to the actual survey data, 70% of the students reported sleeping between 5.7 and 8.7 hours each night: 15.6% reported sleeping more than 8.7 hours; and 0.01 percent reported sleeping 3 or fewer hours. Compared with the predictions you made in the previous question, is the normal model a good approximation for this distribution? Explain. Edit View Insert Format Tools Table 12pt Paragraph B I U A e Tv W