Question 1

The Reeds have five children aged 2,6,9,11,and 14.The median age of the Reed children is

Accepted Answer

The median is the middle value in a list of numbers. When the ages are arranged in order (2, 6, 9, 11, 14), the middle value is 9.

Question 2

Which of the following measures of central tendency is sensitive to extremely high or low scores in a distribution?

Accepted Answer

The mean is sensitive to extremely high or low scores in a distribution because it takes into account every score in the data set when calculating the average. As a result, a very high or low score can significantly affect the value of the mean.

Question 3

Which measure of central tendency indicates the most frequently occurring score in a distribution?

Accepted Answer

The mode is the measure of central tendency that indicates the most frequently occurring score in a distribution. The mean is the average of all scores in a distribution, while the median is the middle score when all scores are arranged in order. The range is a measure of variability that represents the difference between the highest and lowest scores in a distribution.

Question 4

If one wants to find the median of an even number of scores,one

Accepted Answer

When there is an even number of scores, there is no exact middle score. Therefore, the median is calculated by finding the two middle scores and taking their average. This is the best choice as it accurately represents the central tendency of the data set.

Question 5

The 25 students in the psychology class take a 20-point quiz.Five of the students each obtained a score of 10 on the quiz,ten students each obtained a score of 15,and ten students each obtained a perfect scores of 20.What would be the mean of these scores?

Accepted Answer

To find the mean, we need to add up all the scores and divide by the total number of students:

(5 * 10) + (10 * 15) + (10 * 20) = 50 + 150 + 200 = 400

The total number of students is 25, so:

Mean = 400/25 = 16

Question 6

Twenty psychology students took a 10-point practice test.Their scores were as follows: 3,3,4,5,5,5,6,6,6,6,8,8,9,9,9,9,10,10,10,10.What would be the median?

Accepted Answer

The median is the middle number when the scores are arranged in order from lowest to highest. So first we need to arrange the scores in order: 
3, 3, 4, 5, 5, 5, 6, 6, 6, 6, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10
The middle two numbers are both 8, so the median is 8.0.

Question 7

Which of following represents the point in a group of scores where half the values of the group of scores fall below the median and half fall above?

Accepted Answer

The median is the point in a group of scores where half the values of the group of scores fall below the median and half fall above.

Question 8

An advantage of using the mode is that it

Accepted Answer

The mode is defined as the score that occurs most frequently in a distribution. Therefore, it represents the score actually obtained by the greatest number of people. However, it may not be the best choice if the distribution is multimodal (i.e., has more than one mode) or if there is no mode at all.

Question 9

Which measure of central tendency represents the "middle score" in a group of scores?

Accepted Answer

The median represents the middle score in a group of scores. It is the score that separates the higher half of the scores from the lower half, and is not affected by extreme scores or outliers like the mean is. The mode represents the most frequent score, while the range is a measure of variability rather than central tendency.

Question 10

There are ten students in the pre-kindergarten class.Each student is shown eight colors and asked to name them.The number of colors correctly named by each student was: 8,8,8,8,7,7,6,6,5,4.What would be the mean?

Accepted Answer

The mean is calculated by adding all the numbers together and dividing by the number of students: (8+8+8+8+7+7+6+6+5+4)/10 = 67/10 = 6.7.

Question 11

There are ten students in the pre-kindergarten class.Each student is shown eight colors and asked to name them.The number of colors correctly named by each student was: 8,8,8,8,7,7,6,6,5,4.What would be the median?

Accepted Answer

To find the median, we need to arrange the data in ascending or descending order.

4, 5, 6, 6, 7, 7, 8, 8, 8, 8

There are 10 numbers in this data set, an even number. To find the median, we take the average of the two middle numbers. The middle two numbers are 7 and 7. So, the median is (7+7)/2 = 7.0. Therefore, the best choice is C).

Question 12

Measures of central tendency include the mean,median,and

Accepted Answer

The measures of central tendency refer to the typical or central values of a dataset. The mean and median are measures of central tendency, but the range and standard deviation measure variability in the data. The mode, which represents the value that occurs most frequently in the dataset, is also a measure of central tendency. Therefore, the best choice is C - mode.

Question 13

Carla and her five girlfriends went shopping and spent $20,$12,$13,$8,$13,and $9,respectively,on cosmetics.The mode of their expenditures is

Accepted Answer

The mode is the value that appears most frequently in a set of data. In this case, $13 appears twice, which is more than any other value. Therefore, the mode of their expenditures is $13.

Question 14

There are ten students in the pre-kindergarten class.Each student is shown eight colors and asked to name them.The number of colors correctly named by each student was: 8,8,8,8,7,7,6,6,5,4.What would be the mode?

Accepted Answer

The mode of a data set is the value that appears most frequently. In this case, the value 8 appears four times, which is more than any other value. Therefore, the mode is 8.0. The other answer choices do not appear as frequently as 8, therefore they are not the mode.

Question 15

The mean,median,and mode are

Accepted Answer

The mean, median, and mode are all measures of central tendency, which represent the typical or average value of a dataset. In contrast, inferential statistics involve making inferences or predictions about a population based on a sample, measures of variability quantify how spread out the data is, and graphical statistics involve representing data visually.

Question 16

Professor Warren calculated the mean,median,and mode of the scores made on the midterm exam.These descriptive statistics are known as

Accepted Answer

The mean,median,and mode are all measures of central tendency, which are used to provide a summary of the central or typical value in a dataset. The other options, inferential statistics, measures of variability, and graphical statistics, refer to different types of statistical tools or concepts.

Question 17

If you add up all the scores and then divide by the number of scores,you arrive at the

Accepted Answer

The mean is calculated by adding up all the scores and then dividing by the number of scores. This gives the average value for the data set. The other options (median, mode, range) do not involve adding up all the scores and dividing by the number of scores.

Question 18

The 45 students in your psychology section took the test.Your instructor adds together the scores made by these students and divides by 45 to obtain the

Accepted Answer

The mean is obtained by adding all the scores and dividing by the number of students, which is the process described in the question. The median is the middle score when the scores are listed in order, the mode is the most frequent score, and the range is the difference between the highest and lowest scores. None of these concepts require averaging the scores as in finding the mean.

Question 19

One problem with the mean is that it

Accepted Answer

The mean is sensitive to extremely high or low scores, which can skew the overall result. This is because the mean is calculated by adding up all the scores and dividing by the number of scores, so extreme values can heavily influence the result.

Question 20

Leesa arranges her set of scores from the highest to the lowest and then selects the score that falls in the middle.Leesa has determined which measure?

Accepted Answer

The median is the middle value in a list of numbers arranged in order.

Quiz 19: Appendix A: Behavioral Statistics