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Chapter 8: Q.78 (page 521)

Scientists collect data on the blood cholesterol levels (milligrams per deciliter of blood) of a random sample of 24laboratory rats. A 95%confidence interval for the mean blood cholesterol level Mis 80.2to 89.8. Which of the following would cause the most worry about the validity of this interval?

(a) There is a clear outlier in the data.

(b) A stemplot of the data shows a mild right skew.

(c) You do not know the population standard deviation S.

(d) The population distribution is not exactly Normal.

(e) None of these would be a problem because the t procedures are robust.

Short Answer

Expert verified

The correct option is (a).

Step by step solution

01

Given Information

Scientists collect data on the blood cholesterol levels (milligrams per deciliter of blood) of a random sample of 24 laboratory rats.

02

Explanation

If the population standard deviation is unknown, then it is assuming in the t-procedure. But the drawbacks of the t-procedure are various outliers and skewness. Thus, there will be a clear outlier in the data in the confidence interval.

Hence the correct option is (a).

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