chickens. He records his harvest of eggs for 20 days. He finds that the average per day is 290 eggs with a standard deviation of 15. At 5% level of significance, what did the poultry raiser find out?

Each students in a local school district write a national examination. The average on this year national exam is 150 with a standard deviation of 20. Schools where the overall average is between 1.5 and 3.0 standard deviations above the mean are eligible for additional funding. What is the average range a school must achieve to be eligible for funding?

Christian earned a score of 80 on Exam A that had a mean of 200 and a standard deviation of 40. He is about to take Exam B that has a mean of 650 and a standard deviation of 50. How well must Christian score on Exam B in order to do equivalently well as he did on Exam A? Assume that scores on each exam are normally distributed.

Dr. Shoals predicts that people who walk a mile in moderately high heels and very high heels will differ in their levels of reported back pain. 27 participants walk in 4-inch heels and then 2.5-inch heels. He calculates the standard deviation of the difference scores and finds sD = 3.37. What is the standard error of the difference for difference scores?

In a population, the data value 180 has a z score of -0.8. The standard deviation of this population is 32.36. What is the mean of the population?

The lengths of pregnancies in a small rural village are normally distributed with a mean of 263 days and a standard deviation of 13 days.In what range would you expect to find the middle 50% of most pregnancies? Between and.

State two ways the standard deviation differs from the average deviation.

Let’s assume that weight is normally distributed with a mean of 160 and a standard deviation of 25 pounds. The middle 80% 0f all people lie between which two weights?

Assume that adults have IQ scores that are normally distributed with a mean of 100 and a standard deviation 20. Find Upper P 4 which is the IQ score separating the bottom 44​% from the top 96​%.

Suppose the exam average in a class is 55% with a standard deviation of 4. What proportion of students scored above 57%? Round to two places.