Exam 5: The Normal Curve and Standard Scores

A testing bureau reports that the mean for the population of Graduate Record Exam (GRE) scores is 500 with a standard deviation of 90. The scores are normally distributed. The proportion of scores between 300 and 400 is _________.

On a test with a population mean of 75 and standard deviation equal to 16, if the scores are normally distributed, what percentage of scores fall between 70 and 80?

In a normal curve, the inflection points occur at _________.

For any z distribution of normally distributed scores, P 50 is always equal to zero.

The normal curve never touches the X axis.

The z score corresponding to the mean of a raw score distribution equals _________.

Would you rather have an income (assume a normal distribution and you are greedy) _________.

A z transformation will allow comparisons to be made when units of distributions are different.

Using the data in problem 19, what is the height below which the shortest 2.5% of the college males fall and what is the height above which the tallest 2.5% fall?

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of $8.52 with a standard deviation of $2.38. What percentage of the distribution lies between $5 and $11?

To calculate the score at the 97.5th percentile, one would apply the formula X = µ + ( s )(1.96).

Makaela took a Spanish exam; her grade was 79. The distribution was normally shaped with = 70 and s = 12. Juan took a History exam; his grade was 86. The distribution was normally shaped with = 80 and s = 8. Which did better on their exam relative to those taking the exam?

On a test with a population mean of 75 and standard deviation equal to 16, if the scores are normally distributed, what is the percentile rank of a score of 56?

A testing bureau reports that the mean for the population of Graduate Record Exam (GRE) scores is 500 with a standard deviation of 90. The scores are normally distributed. The proportion of scores that lie above 650 is _________.

The standard deviation of the z distribution equals _________.

What z scores correspond to the following percentile ranks? Assume the scores are normally distributed.

Are all bell-shaped curves normal curves? Explain.

A stockbroker has kept a daily record of the value of a particular stock over the years and finds that prices of the stock form a normal distribution with a mean of $8.52 with a standard deviation of $2.38. What percentage of the distribution lies below $7.42.

Assuming that you wished to have the highest possible score on an exam relative to the other scores; would you rather have a score of 70 on a test with a mean of 60 and a standard deviation of 5.2 or a score of 81 on a test with a mean of 70 and a standard deviation of 7.1?

In the standard normal curve, 13.59% of the scores will always be contained between the mean ( µ ) and +1 s .