Question

As part of a study investigating the effects of vigorous exercise on risk of coronary heard disease, researchers measured HDL concentrations (mg/dL) in a sample of 19 male marathon runners as well as in a sample of 32 men who do not regularly exercise. The data are summarized below:

Marathon runners: Mean | 51.3 mg/dL St. Dev.| 14.2 mg/dL

Do not exercise: Mean | 44.0 mg/dL St. Dev. 15.0.mg/dL

a. Assuming that the two distributions of HDL concentrations are normally distributed with equal variances, run the appropriate test to determine if there is a significant difference between marathon runners and men who don’t exercise. Given: ???????? = 2.00 and ??!""#$% = 2.43 ??/??

b. Name a possible confounding variable in this analysis and what impact it might have on the applicability of the results. (

Answer 1

solution : HDL Con Centrations (mg /ou) im, Sample of 19 male Marathon runners ima 19 And Sample of 32 Men who do not Regularly Exessise : no: 32 Consider : X,: HDL Concentrations (mglom) in Male Marathon Runners. X2 : HDL. Concentrations (mglow in Mean who do not Regolarly Exercise. Given That, 7, Sample Hean 51.3 mg lade si a stDer -14.2 mg labu Xq: Sample mean = 44.0 s st. Der - 15.0 pooled S.E - 2.43. mgIdb. Hypothesis is. Ho: These is no significant Diffarance between Marathon Runners and Men who Don't Exercise (c D-Seemned with CamScanner

Hi : These is significant Marathon Rummers and Men Diffrance who don't Between Exercise. Tes4 slol:se , t - X - 8, 1 + Pooled S.E. = : Splim ng = 2.43 mg/dl (given) t. 51-3 – 44.0 2.43 : 3.0041 t Coilical = 2.009 (given) Hese taal. = 3.0041 > to = 2:00. .: We Reject Ho at 5% do O.S. Conclusion : There on signüficant Diffarance Between. Marathon Runness and Men who don't Exercise - THE END - cs Scanned with CamScanner