Chapter 6.7, Problem 6.105ACI

Is honey a cough remedy? Refer to the Archives of Pediatrics and Adolescent Medicine (December 2007) study of honey as a remedy for coughing, Exercise 2.31 (p. 62). Recall that the 105 ill children in the sample were randomly divided into groups. One group received a dosage of an over-the-counter cough medicine (DM); another group received a dosage of honey (H). The coughing improvement scores (as determined by the children’s parents) for the patients in the two groups are reproduced in the accompanying table. The pediatric researchers desire information on the variation in coughing improvement scores for each of the two groups.

1. a. Find a 90% confidence interval for the standard deviation in improvement scores for the honey dosage group.
2. b. Repeat part a for the DM dosage group.
3. c. Based on the results, parts a and b. what conclusions can the pediatric researchers draw about which group has the smaller variation in improvement scores? (We demonstrate a more statistically valid method for comparing variances in Chapter 8.)

Honey Dosage	11 12 15 11 1013 10 4 15 16 9 14 10 6 1011 12 12 8 12 9 11 15 10 15 9 138 12 1095 12
DM Dosage	4694 7779 12 10 11 6349 12 768 12 12 4 12 137 10 13944 10 159