Purpose: To gain experience computing confidence intervals for means. Fill out t
ID: 3064941 • Letter: P
Question
Purpose: To gain experience computing confidence intervals for means. Fill out this sheet and turn it in. Confidence Intervals for Means. In this lab we will compute confidence intervals for means using data from study on men's health. Open the Excel worksheet "mhealth" on the STT 1600 Lab Webpage (https://science-math.wright.edu/math-statistics/resources/stt-1600-labs-for section-11-wellinghoff Compute a 95% confidence interval for men's pulse rates (note that the pulse rates area in column F). To do this, click in an empty cell and type "-AVERAGE(F2.F41l" to get the 1, average pulse rate for the ne40 men in this sample. Compute the standard deviation of the pulse rates by clicking in another empty cell and typing" STDEV(F2:F41). To get the t-critical value, click in an empty cell and type" TINV(0.05,39)". Note that 39 n-1 is the degrees for freedom for the t-critical value. Average: Standard Deviation: L3 t-critical value:-102 r Limit: 10.13Upper Limit: 11,91 Repeat #1, but for this problem compute a 90% confidence interval for the mean pulse rate. Write an interpretation for your confidence interval. Lower Limit:10.93 Interpretation 2. Upper Limit 11.1 we are 40% conident tnat tre ihtcval 10.43 10 1117Cantains tme intevaly for meah which confidence interval is narrower, the 95% or the 90% interval? 3, The 90% meen al. 4. Compute a 95% confidence interval for the mean BMI (from in column Lower Limit: Repeat #4, but compute a 90% confidence interval. Upper Limit:3.57 40 0.11 5. Lower Limit:3.2t Upper Limit: 3.56 .40 40 0.14 . The z-score separaungExplanation / Answer
The data source is missing, it says invalid URL. I have calculated below assuming that the average and standard deviation values mentioned are correct.
Average = 69.4; Standard deviation = 11.3; t0.05,39 = 2.0227
Standard error = standard deviation of sample / sqrt(n) = 11.3 / sqrt(40) = 1.7867
Lower Limit of mean = 69.4 - 2.0227 x 1.7867 = 65.7861
Upper LImit of mean = 69.4 + 2.0227 x 1.7867 = 73.0139
2. For 90% confidence limits, t0.1,39 = 1.6849
Lower Limit of mean = 69.4 - 2.0227 x 1.6849 = 66.3897
Upper LImit of mean = 69.4 + 2.0227 x 1.6849 = 72.4103
Interpretation: A 90% confidence interval has a 0.9 probability of containing the population mean
3. The 95% interval is narrower.
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