Questions from Essentials of Statistics

Q: In 1908, W. S. Gosset published “The Probable

In 1908, W. S. Gosset published “The Probable Error of a Mean” (Biometrika, Vol. 6, pp. 1–25). In this pioneering paper, published under the pseudonym “Student,” he introduced what later became known...

Q: Anorexia nervosa is a serious eating disorder, particularly among young women

Anorexia nervosa is a serious eating disorder, particularly among young women. The following data provide the weights, in pounds, of 17 anorexic young women before and after receiving a family therapy...

Q: R. Stichler et al. compared two methods of measuring treadwear

R. Stichler et al. compared two methods of measuring treadwear in their paper “Measurement of Treadwear of Commercial Tires” (Rubber Age, Vol. 73:2). Eleven tires were each measured for treadwear by t...

Q: The Information Please Almanac provides the number of children of each of

The Information Please Almanac provides the number of children of each of the U.S. presidents. A frequency histogram for number of children by president, through President Barack H. Obama, is as follo...

Q: Glaucoma is a leading cause of blindness in the United States.

Glaucoma is a leading cause of blindness in the United States. N. Ehlers measured the corneal thickness of eight patients who had glaucoma in one eye but not in the other. The results of the study wer...

Q: Cooling down with a cold drink before exercise in the heat is

Cooling down with a cold drink before exercise in the heat is believed to help an athlete perform. Researcher J. Dugas explored the difference between cooling down with an ice slurry (slushy) and with...

Q: Refer to Exercise 10.123. a. Determine a

Refer to Exercise 10.123. a. Determine a 95% confidence interval for the difference between the mean heights of cross-fertilized and self-fertilized Zea mays. b. Repeat part (a) for a 99% confidence l...

Q: we have presented a confidence interval (CI) for the difference

we have presented a confidence interval (CI) for the difference, μ1 − μ2, between two population means. Interpret each confidence interval. 95% CI is from 15 to 20.

Q: Refer to Exercise 10.124. a. Determine a

Refer to Exercise 10.124. a. Determine a 90% confidence interval for the additional sleep that would be obtained, on average, by using laevohysocyamine hydrobromide. b. Repeat part (a) for a 98% confi...

Q: Refer to Exercise 10.125 and find a 90% confidence

Refer to Exercise 10.125 and find a 90% confidence interval for the weight gain that would be obtained, on average, by using the family therapy treatment. Data from Exercise 10.125: Anorexia nervosa...