Exam 8: Bell-Shaped Curves and Other Shapes

For Questions , use the following narrative Narrative: Entrance exam Suppose a certain college has its own entrance exam, and scores on this exam follow a normal distribution with mean 150 and standard deviation 20. -{Entrance exam narrative} Bob's score on this exam was 130.What is Bob's standard score, and what does this mean in terms of where he stands in this population?

For Questions , use the following narrative Narrative: Entrance exam Suppose a certain college has its own entrance exam, and scores on this exam follow a normal distribution with mean 150 and standard deviation 20. -{Entrance exam narrative} Sue's standard score on this exam was −1.5.What was her original score?

Which of the following measurements likely has a normal distribution, at least approximately?

Some easy-to-remember intervals can give you a picture of where the values on any normal curve will fall.This information is known as the __________.

For Questions , use the following narrative Narrative: Snake lengths Suppose the lengths of a certain species of snake have a normal distribution with a mean of 45 inches. -{Snake lengths narrative} Draw a picture of the distribution of snake lengths for this population.

What is another term for measurements following a 'normal distribution'?

For any normal curve, almost all of the values will fall within __________ of the mean.

For Questions , use the following narrative Narrative: Snake lengths Suppose the lengths of a certain species of snake have a normal distribution with a mean of 45 inches. -{Snake lengths narrative} What percentage of the snakes in this population are 45 inches long or longer?

For Questions , use the following narrative Narrative: Snake lengths Suppose the lengths of a certain species of snake have a normal distribution with a mean of 45 inches. -{Snake lengths narrative} Explain what it means for the snake lengths to have a bell-shaped distribution (use words that a non-statistician would understand).

For Question use the following narrative Narrative: Grades Suppose a professor sees that his students' exam scores do not follow a normal curve, but he decides to assign grades by "grading on a bell-shaped curve" anyway. -{Grades narrative} Explain how this procedure tends to distort the grades.

Your __________ in a population represents the position of your measurement in comparison with everyone else's.

For Questions , use the following narrative Narrative: Entrance exam Suppose a certain college has its own entrance exam, and scores on this exam follow a normal distribution with mean 150 and standard deviation 20. -{Entrance exam narrative} Bob's score on this exam was 130.What was Bob's percentile, and what does this mean in terms of how he compares to the rest of the population?

For Questions use the following narrative Narrative: Men's heights Suppose the mean height for adult males in the U.S.is about 70 inches and the standard deviation is about 3 inches.Assume men's heights follow a normal curve. -{Men's heights narrative} Using the Empirical Rule, approximately what percentage of adult males are under 64 inches tall?

Suppose your score on the GRE (Graduate Records Exam) was at the 90th percentile.What does that mean?