Testing Effects of Physical Training A study was conducted to investigate some effects of physical training. Sample data are listed below, with all weights given in kilograms. (See “Effect of Endurance Training on Possible Determinants of VO2 During Heavy Exercise,” by Casaburi et al., Journal of Applied Physiology, Vol. 62, No. 1.)

a. Is there sufficient evidence to conclude that there is a difference between the pretraining and posttraining weights? What do you conclude about the effect of training on weight?

b. Construct a 95% confidence interval for the mean of the differences between pretraining and posttraining weights.

Pretraining: 99 57 62 69 74 77 59 92 70 85 Posttraining: 94 57 62 69 66 76 58 88 70 84