Arrhythmia, or an irregular heart beat, may be caused by heart disease or by environmental factors such as stress, caffeine, tobacco, or even cold medicine. One type of arrhythmia is atrial flutter,...

Arrhythmia, or an irregular heart beat, may be caused by heart disease or by environmental factors such as stress, caffeine, tobacco, or even cold medicine. One type of arrhythmia is atrial flutter, in which the heart beats very fast, at over 250 beats per minute. In a recent research study, randomly selected patients identified to have atrial flutter were carefully monitored. The number of beats per minute for the most recent flutter for each patient, by sex, is given on the text website. Assume the underlying distribution of beats per minute in atrial flutter patients is normal.

 a. Find a 98% confidence interval for the true mean beats per minute in male atrial flutter patients.

 b. Find a 98% confidence interval for the true mean beats per minute in female atrial flutter patients.

 c. Using your answers to parts (a) and (b), is there any evidence to suggest the true mean beats per minute in atrial flutter patients is different for men and women? Justify your answer.

 d. Do you think the normality assumption is reasonable in this case? Why or why not?