ALL ABOUT STATS

1. The number of calories burned after a brisk walk at 5 km/hr for an hour is normally distributed with a mean of 300 calories and a standard deviation of 8 calories. Find the probability that a randomly selected hiker who walks at this pace for one hour burns: a. Less than 295 calories b. More than 310 calories c. Between 285 and 305 calories 2. The length in days of human pregnancies is known to be normally distributed with a mean of 266 days and a standard deviation of 16 days. a. between what number of days do the middle 95% of all pregnancies fall? b. How long do the shortest 2.5% of all pregnancies last? c. How long do the longest 5% of all pregnancies last? d. If a pregnant woman is randomly chosen, what is the probability that her pregnancy will last longer than 270 days