Question 1

What is the mean of the following distribution of scores: 2,5,8,10,11,4,6,9,1,4?

Accepted Answer

To find the mean, we add up all the scores and divide by the total number of scores. 
2+5+8+10+11+4+6+9+1+4 = 60
60 / 10 = 6

Question 2

The ________ can be a particularly misleading indication of what is average for a ________ distribution of scores.

Accepted Answer

The median is the middle score in a distribution, which can be a better representative of the average in a skewed distribution where extreme scores can significantly influence the mean. However, in a normal distribution, the mean and median are usually very similar and can both be used as measures of central tendency.

Question 3

The first step in constructing a bar graph is to

Accepted Answer

The first step in constructing a bar graph is to organize the data. This involves gathering the data and categorizing it into groups or categories, which will serve as the basis for the bars on the graph. Without organized data, it is impossible to create an accurate and meaningful bar graph. Measuring standard deviation, calculating correlation coefficients, and determining range may be important later steps in data analysis, but they are not the first step in creating a bar graph.

Question 4

Which of the following is NOT a measure of central tendency?

Accepted Answer

Range is a measure of dispersion, not central tendency. Mean, median, and mode are all measures of central tendency.

Question 5

Differences between two samples are LEAST likely to be statistically significant if the samples are ________ and the standard deviations of the samples are ________.

Accepted Answer

When samples are small and the standard deviations are large, it indicates a high level of variability within each sample. This high variability makes it more difficult to detect a true difference between the two samples, thus making differences less likely to be statistically significant.

Question 6

Why is the median at times a better measure of central tendency than the mean?

Accepted Answer

The median is less sensitive to extreme scores because it is not influenced by outliers in the way that the mean is. Therefore, it can sometimes be a better measure of central tendency in distributions with extreme scores.

Question 7

When people's symptoms of emotional distress are at their worst,whatever they do to try to alleviate the condition is likely to be followed by improvement rather than further deterioration. This is best explained in terms of

Accepted Answer

This phenomenon is known as regression toward the mean, which is a statistical concept referring to the tendency for extreme scores on a variable to be followed by scores that are closer to the average or mean. In this case, symptoms of emotional distress that are particularly severe are likely to be followed by improvement regardless of what the individual does, simply because extreme symptoms are less likely to persist over time.

Question 8

What is the mode of the following distribution: 8,2,1,1,3,7,6,2,0,2?

Accepted Answer

The mode is the number that appears most frequently in the distribution. In this case, the number 2 appears three times, which is more than any other number in the distribution, making it the mode. Therefore, the best choice is B.

Question 9

Five members of Terry's sorority reported the following individual earnings from their sale of raffle tickets: $3,$6,$8,$6,and $12. In this distribution,the mean is ________ the mode and ________ the median.

Accepted Answer

The mode is the most frequently occurring value, which in this case is $6 (since two members earned $6 each). The median is the middle value when the earnings are arranged in numerical order, which is also $6 in this case.

To calculate the mean, we add up all the earnings and divide by the total number of members:

$(3+6+8+6+12) ÷ 5 = $7

Therefore, the mean is greater than both the mode and the median.

Question 10

The maximum height of a normal curve corresponds to the ________ of a normal distribution.

Accepted Answer

The maximum height of a normal curve corresponds to the mean of a normal distribution. This is because the curve is symmetrical around the mean, so the highest point must be at the mean. The range and standard deviation do not determine the maximum height of the curve, and statistical significance is not a property of a normal distribution.

Question 11

The most frequently occurring score in a distribution is the

Accepted Answer

The mode is the score that appears most frequently in a distribution, so it is the correct answer. The mean is the average score, the median is the middle score, and the range is the difference between the highest and lowest scores, but none of them necessarily indicate the most frequently occurring score.

Question 12

Which score falls at the 50th percentile of a distribution?

Accepted Answer

The 50th percentile refers to the score at which 50% of the distribution falls below and 50% falls above. This is the definition of the median, which is the middle score in an ordered distribution. Therefore, the answer is the median (choice B).

Question 13

What is the median of the following distribution: 10,7,5,11,8,6,9?

Accepted Answer

To find the median, we need to first arrange the data in order: 5,6,7,8,9,10,11. The middle number is 8, which is the median.

Question 14

Standard deviation is to mode as ________ is to ________.

Accepted Answer

Standard deviation measures the variation in a data set, while mode represents the most frequently occurring value. Similarly, mean represents the central tendency of a data set, while variation (in the form of range or interquartile range) represents the spread of the data set. Therefore, the correct analogy is between variation and central tendency.

Question 15

In the following distribution,the mean is ________ the mode and ________ the median: 4,6,1,4,5.

Accepted Answer

The answer of In the following distribution,the mean is ________...

Question 16

The ________ is a measure of ________.

Accepted Answer

The standard deviation is a measure of variation, specifically the average amount by which the values in a dataset deviate from the mean. The other options are incorrect: the median is a measure of central tendency, not variation; the range is another measure of variation, but not related to central tendency; and the correlation coefficient is a measure of the strength and direction of the relationship between two variables, not central tendency.

Question 17

Bob scored 43 out of 70 on his psychology exam. He was worried until he discovered that most of the class earned the same score. Bob's score was equal to the

Accepted Answer

Bob's score being the same as most of the class indicates it is the most frequently occurring score, which defines the mode.

Question 18

What is the median of the following distribution of scores: 1,3,7,7,2,8,4?

Accepted Answer

First, arrange the scores in ascending order: 1, 2, 3, 4, 7, 7, 8. The median is the middle number, which is 4.

Question 19

What is the mean of the following distribution of scores: 2,3,7,6,1,4,9,5,8,2?

Accepted Answer

To find the mean, we sum up all the scores and divide by the total number of scores:

(2+3+7+6+1+4+9+5+8+2) ÷ 10 = 4.7

Therefore, the correct answer is C, with a mean of 4.7.

Question 20

What is the mode of the following distribution of scores: 2,2,4,4,4,14?

Accepted Answer

The mode is the score that appears most frequently in the distribution. In this case, the score of 4 appears 3 times, which is more than any other score. Therefore, the mode of this distribution is 4.

Quiz 3: Self-Concept: Who Am I