Question

In a 1868 paper, German physician Carl Wunderlich reported based on over a million body temperature readings that the mean body temperature for healthy adults is 98.6° F. However, it is now commonly believed that the mean body temperature of a healthy adult is less than what was reported in that paper. To test this hypothesis a researcher measures the following body temperatures from a random sample of healthy adults.

98.2, 98.5, 98.6, 98.5, 97.4, 98.3

(a)	Find the value of the test statistic.

(b)	Find the 10% critical value.

(c)	Since the sample size is less than 30, the above analysis requires that the population follows a normal distribuiton. What method could be used to check this assumption?

options for c

(A) check to see if the answer in (a) is less than the answer in (b). (B) Check to see if the p-value in (c) above is greater than .10. (C) Draw a normal probability plot, and see if the points are bell-shaped (like the normal curve). (D) Check to see if the p-value in (c) above is less than the α value. (E) One-sample z-test for a population mean. (F) Draw a normal probability plot, and see if the points fall close to a straight line. (G) check to see if the answer in (a) is greater than or equal to the answer in (b). (H) One-sample t-test for a population mean

Answer 1

a)

value of the test statistic. t =-1.9415 ~ -1.941

b)

0.1 level with left tailed test and n-1= 5 df, critical t=

-1.476

c)

(F) Draw a normal probability plot, and see if the points fall close to a straight line