Exam 6: Statistical Concepts: Making Meaning Out of Raw Scores

If an individual takes a test, and if you know an individual's raw score, the mean of the group of individuals who took the test, and the standard deviation of the group, you can tell the relative position of the individual within his or her group.

What is the standard deviation of the following groups of scores?

On a normally distributed curve, which is true?

Histograms and frequency polygons are visual representations of frequency distributions.

A group of graduate students studying psychology take a national comprehensive exam. On the test, their mean score is about 0.5 standard deviation above the mean as compared to the national score. The variability of their scores is less than the national mean. If passing is 1 standard deviation below the mean, it is likely that many have failed.

Approximately 2 percent of people do lower than 3 standard deviations below the mean.

Exhibit 6-1 -Using the numbers in Exhibit 6-1, draw a frequency polygon using class intervals of 3.

Which of the following is the best method for determining the percentile rank regarding a group of scores?

What is the range of the following groups of scores: 4, 7, 8, 8, 9, 10, 12, and 14?

Exhibit 6-1 -Refer to Exhibit 6-1. Create a frequency distribution from the set of scores.

Exhibit 6-2 In order to evaluate a graduate program in counseling, a decision is made to compare the scores of the recent graduates on the National Counseling Exam (NCC) to the national norms. Therefore, the program decides to compare its current graduates with the all graduates nationally who took the exam. Their scores of the current graduates are as follows: -Refer to Exhibit 6-2. Find the mean.

Exhibit 6-1 -Using the numbers in Exhibit 6-1, determine the mode.

Exhibit 6-1 -Using the numbers in Exhibit 6-1, if you want to end up with four bars on your histogram, how many numbers should be in each interval?

If Juan has scored a 53 on a test, what can we say about how he has done?

Exhibit 6-1 -Using the numbers in Exhibit 6-1, determine the range.

Approximately 84 percent of people do higher than 1 standard deviation below the mean.

Exhibit 6-1 -Using the numbers in Exhibit 6-1, determine the interquartile range.

Exhibit 6-2 In order to evaluate a graduate program in counseling, a decision is made to compare the scores of the recent graduates on the National Counseling Exam (NCC) to the national norms. Therefore, the program decides to compare its current graduates with the all graduates nationally who took the exam. Their scores of the current graduates are as follows: -Refer to Exhibit 6-2. Find the interquartile range.

On a negatively skewed curve, which of the following is true?

Use the data from Exhibit 6-2. If the national mean is 25, and the standard deviation is 8, who has done better: the graduate program or the national group?