13.7 More on pulse rates. Let’s again assume that the resting pulse rates for healthy adults follow a Normal distribution with a mean of 69 beats per minute and a standard deviation of 9.5 beats per minute. When converted to a standard score, Adam’s pulse rate becomes −0.5. How should this standard score be interpreted?
(a) Adam should see a doctor because his pulse rate is unusually low.
(b) Adam’s pulse rate is above the mean.
(c) Exactly 5% of healthy adults have pulse rates less than Adam’s pulse rate.
(d) Adam’s pulse rate is about one-half of a standard deviation below the mean.