Exam 8: Bell-Shaped Curves and Other Shapes

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, 95% of adult males should fall into what height range?

Suppose you took a standardized test and the scores had a bell-shaped distribution.You only need three pieces of information in order to find your percentile in the population of test scores.What are those three pieces of information?

Nature provides numerous examples of populations of measurements that, at least approximately, follow a normal curve.Give one example.

Suppose a population generally follows a normal curve, except that one of the measurements on this curve falls more than 3 standard deviations above the mean.What would you call this value?

The bell-shaped frequency curve is so common that if a population has this shape, the measurements are said to follow a __________ distribution.

{Entrance exam narrative} [Normal table or calculator required.] Bob's original score was 130 and Jill's standard score was +1.5.What percentage of the students taking this exam had scores that fell between Bob and Sue's scores?

What is the best way to represent the shape of a large population of measurements?

Which of the following describes the entire area underneath a frequency curve?

With a frequency curve, to figure out what percentage or proportion of the population falls into a certain range, you have to figure out the __________ under the curve over that range.

Are all frequency curves bell-shaped? If yes, explain why.If no, give an example of one that is not.

The Empirical Rule says that for a normal curve, approximately 68% of the values fall within 1 standard deviation of the mean in either direction, while 95% of the values fall within 2 standard deviations of the mean in either direction.Explain why you don't have twice as many values within 2 standard deviations as you do within 1 standard deviation.

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 between 64 and 73 inches tall?

Which of the following is not true about a standard normal curve?

Suppose one individual in a certain population had a z-score of −2.Which of the following is true?

In a frequency curve, how do you interpret the height of the curve at any particular point?

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 below 73 inches tall?

Which of the following describes measurements that have a normal distribution?

What do you need to check for first, before using the Empirical Rule to describe a 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, 68% of adult males should fall into what height range?

A(n) __________ represents the number of standard deviations the observed value or score falls above or below the mean.