Question

Question 7 View Policles Current Attempt in Progress Is Fast Food Messing With Your Hormones? Examine the results of a study investigating whether fast food consumption increases one's concentration of phthalates, an ingredient in plastics which has been linked to multiple health problems including hormone disruption. The study included 8877 people who recorded all the food they ate over a 24-hour period and then provided a urine sample. Two specific phthalate byproducts were measured (in ng/mL) in the urine: DEHP and DiNP. Find a 95% confidence interval for the difference·1F-Ha. in mean concentration between people who have eaten fast food in the last 24 hours and those who haven't. The mean concentration of DEHP in the 3095 participants who had eaten fast food wasF 83.6 with sp 194.7 while the mean for the 5782 participants who had not eaten fast food was 59.1 with sN152.1 Round your answers to one decimal place. The 95% confidence interval is to Zota, A.R., Phillips, C.A, Mitro, S.D, Recent Fast Food Consumption and Bisphenol A and Phthalates Exposure among the U.S. Population in NHANES, 2003-2010; Environmental Health Perspectives, 13 April, 2016. Question 8 0/2 iew Policies how Attempt History urrent Attempt in Progress Incorrect. Impact of College Roommates on Grades In this exercise, we investigate answers to the questions: How much of an effect does your roommate have on your grades? In particular, does it matter whether your roommate brings a videogame to college? A study was conducted involving n = 210 first-year students who were randomly assigned a roommate. Table 1 gives summary statistics on grade point average GPA or the first semester depending on whether the student and/or the roommate brought a videogame to campus. Student mate brought brought Sample size Mean GPA St. Dev. videogame videogame No 3.128 3.039 2.932 2.754 0.590 0.689 0.699 0.639 No No 38 No Yes 40 Table 1 Videogames and GPA Considering only students who do not bring a videogame to campus, find a 90% confidence interval for the difference in mean GPA between students whose roommate does not bring a videogame and those whose roommate does bring a videogame μΝ fly where μ v represents the mean GPA for students whose roommate does not bring a videogame and represents the mean GPA for students whose roommate does bring a Round your answers to three decimal places. The 90% confidence interval is to Question 9 View Policies Current Attempt in Progress Impact of College Roommates on Grades In this exercise, we investigate answers to the questions: How much of an effect does your roommate have on your grades? In particular, does it matter whether your roommate brings a videogame to college? A study was conducted involvingn 210first-year students who were randomly assigned a roommate. Table 1 gives summary statistics on grade point average (GPA) for the first semester depending on whether the student and/or the roommate brought a videogame to campus. Roommate brought brought Sample size Mean GPA St. Dev. videogame videogame No No 3.128 3.039 2.932 2.754 0.590 0.689 0.699 0.639 No 38 No Yes Yes 40 Table 1 Videogames and GPA Considering only students whose roommate does not bring a videogame to campus, find a 99% confidence interval for the difference in mean GPA between students who bring a videogame and those who do not bring a videogame μΝ-m, where μΝ represents the mean GPA for students who do not bring a videogame andHy represents the mean GPA for students who do bring a videogame. Round your answers to three decimal places. The 99% confidence interval is to Question 11 1.5/2 View Policies Show Attempt History Current Attempt in Progress Use the t-distribution and the given sample results to complete the test of the given hypotheses. Assume the results come from random samples, and if the sample sizes are small, assume the underlying distributions are relatively normal. Test o : μτ .c vs Ha ‘r

Answer 1

7:

Since sample sizes are large so we need to use z critical value instead of t critical value.

Here we have -83.6,σ1-194.7, =59.1,G-152.1, ni:3095 n,-5782 0.05 Confidence level: CL 0.95 Level of significance: Critical value: z 1.96 The standard error is: SE sqrt( (37908.09/3095)+(23134.41/5782)) 1 112 = 4.031 Margon of error: ME-t. SE -7.9008 Confidence interval is: (4-5) ME-(83.6-59.1) 7.9008 (16.5992, 32.4008) Excel function for critical value: NORMSINV(1-(0.05/2)) Hence, the required confidence interval is (16.5992,32.4008)

Answer: ( 16.6, 32.4)