The amount of snowfall falling in a certain mountain range is normally distributed with 80 inches and a standard deviation of 20 inches. What is the probability that the mean annual snow falling during 25 randomly picked years will exceed 72.8 inches?

Trucks in a delivery fleet travel a mean of 80 miles per day with a standard deviation of 35 miles per day. The mileage per day is distributed normally. Find the probability that a truck drives between 108 and 157 miles in a day. Round your answer to four decimal places.

A student will spend 15 hours average each week in class. If the standard deviation is 2 hours, what percentage of students spend less than 12 hours in class?

Suppose the average distance of a Major League Baseball homerun is normally distributed with 558 feet and standard deviation 28 feet. Find the probability that a random homerun will be between 545.96 and 587.96 feet.Enter your answer as a number accurate to 4 decimal places. *Note: all z-scores must be rounded to the nearest hundredth.

Trucks in a delivery fleet travel a mean of 8080 miles per day with a standard deviation of 3030 miles per day. The mileage per day is distributed normally. Find the probability that a truck drives at least 5252 miles in a day. Round your answer to four decimal places.

The amount of time people spend at the gym follows a uniform distribution from 45 to 90 minutes. What is the standard deviation for this uniform distribution?

The IQ of highschool seniors is normally distributed with a mean of 100 and a standard deviation of 15. What is the probability that a sample of 15 students will have a sample mean less than 99.  Give your answer to three decimal places and write as a proportion (i.e. between 0 and 1).

The weights of steers in a herd are distributed normally. The standard deviation is 200lbs and the mean steer weight is 1300lbs. Find the probability that the weight of a randomly selected steer is between 1000 and 1437⁢lbs. Round your answer to four decimal places.

SAT tests have a mean of 500 and a standard deviation of 100. They are normally distributed. Amy got a 640. What percentile is she in?

The weights of steers in a herd are distributed normally. The standard deviation is 200lbs and the mean steer weight is 1400lbs. Find the probability that the weight of a randomly selected steer is between 1539 and 1679lbs. Round your answer to four decimal places.