Exam 6: Z-Scores and the Normal Curve

Your sense of direction puts you at the 39th percentile,relative to a raw score distribution with a mean of 3.5 and a standard deviation of 1.What is your z-score?

Only the upper 30% of a normally distributed class passed a quiz for which the mean was 70 and the standard deviation was 10.In this class,76.7 and 78.4 are the boundary limits for students who scored between what percentiles?

Bahatamy Academy has an outrageously intelligent student body.In a recent evaluation of all the high schools in the state,Bahatamy Academy received a z-score of +3 for its corresponding sample mean of SAT scores.With a population mean of 500 and a standard deviation (standard error)of 200 for the sampling distribution,what was Bahatamy's sample mean?

In a normal distribution,large,positive z-scores occur with _______________ small,positive z-scores.

How accurately the standard normal curve model predicts the actual relative frequency of raw scores depends on three aspects of the data:

Your sense of direction puts you at the 79th percentile,relative to a raw score distribution with a mean of 3.5 and a standard deviation of 1.What is your z-score?

Using the appropriate values from the z-table in the textbook appendix,find the z-score for which the area beyond z in the tail is 0.2546.

For a distribution with = 50 and = 5,find the z-scores for each of the following raw scores: 50;65;45;42

For each of the following z-scores,what is the area beyond the z-score in the tail? 0.63;1.65;1.94;2.27;2.80

For the following set of scores,what is the percentile for a score of 24? 22,23,19,25,26,22,19,25,22,20,21,23,23,24,18,20,22,24,21,21,20,24,22,21,23

The z-score transformation is a useful statistical tool because it enables statisticians to

When two normal z-distributions are plotted on the same graph,what can we say about the relative frequency of each z-score?

What raw score is at the 16th percentile (15.87 to be exact)when the mean of the distribution is 50 and the standard deviation is 4?

In sampling distributions,all the samples contain sets of raw scores

We can use the standard normal curve as our model for

A z-score of zero always means that

One way to measure the ability to find one's way in an environment is to use the Sense of Direction test scale.The scale ranges from 1 (poor)to 50 (good).In a sample of college students,including yourself,the mean rating of sense of direction is 30,with a standard deviation of 10.If your score was 20,what is your z-score?

A perfect normal curve,which serves as a model of any approximately normal z-distribution,is called the

If the population variance of the raw scores equals 169 and the sample size is 121,what is the standard error of the mean?

The distribution of z-scores is always