Suppose that blood chloride concentration (mmol/L) has a normal distri- bution with mean 104 and standard deviation 5 (information in the article \Mathematical Model of Chloride Concentration in Human Blood," J. of Med. Engr. and Tech., 2006: 25{30, including a normal probability plot as described in Section 4.6, supports this assumption).

What is the probability that chloride concentration di ers from the mean by more than 1 standard deviation?

32% probability that chloride concentration differs from the mean by more than 1 standard deviation

Step-by-step explanation:

The Empirical Rule states that, for a normally distributed random variable:

68% of the measures are within 1 standard deviation of the mean.

95% of the measures are within 2 standard deviation of the mean.

99.7% of the measures are within 3 standard deviations of the mean.

What is the probability that chloride concentration di ers from the mean by more than 1 standard deviation?

By the Empirical Rule, there is a 68% probability that the chloride concentration differs from the mean by one standard deviation or less.

100 - 68 = 32.

32% probability that chloride concentration differs from the mean by more than 1 standard deviation