Question 1

Compute the mean from the following set of scores.  &#10;A) 33&#10;B) 5.5&#10;C) 55&#10;D) 4.5

Accepted Answer

The mean is calculated by adding all the numbers together and then dividing by the count of numbers. Here, $5 + 4 + 7 + 3 + 9 + 5 = 33$, and there are 6 numbers, so $33 / 6 = 5.5$.

Question 2

What is the sum of deviations in the above data?&#10;A) 0&#10;B) 33&#10;C) 5.5&#10;D) -.5

Accepted Answer

The sum of deviations from the mean in any data set is always 0. This is because deviations are calculated as the difference between each data point and the mean of the dataset, and by definition, the sum of these differences above the mean is equal to the sum of the differences below the mean.

Question 3

Which of the following is NOT true about the mean?&#10;A) Mean is the most frequently used average&#10;B) It is the sum of the scores divided by the number of scores&#10;C) Mean is the balance point in a distribution of scores&#10;D) Mean measures the deviations of each score&#10;E) It is the point around which all the deviations sum to zero

Accepted Answer

Mean does not measure the deviations of each score; it is a measure of central tendency. The statement about mean measuring deviations of each score is incorrect; instead, mean is calculated as the sum of all scores divided by the number of scores, and it serves as a balance point in a distribution.

Question 4

To how many decimal places are the means reported in journals?&#10;A) One decimal place&#10;B) Two decimal places&#10;C) Three decimal places&#10;D) Four decimal places

Accepted Answer

Means are typically reported to two decimal places in journals to provide a balance between precision and readability.

Question 5

The mean is almost always inappropriate for describing the average of a highly skewed distribution. __________

Accepted Answer

The mean can be heavily influenced by outliers in a highly skewed distribution, making it a less reliable measure of central tendency compared to the median in such cases.

Question 6

The mean is appropriate for use with any scales of measurements. _________

Accepted Answer

The mean is only appropriate for interval and ratio scales of measurement, not for nominal or ordinal scales.

Question 7

The mean is pulled in the direction of extreme scores. _________

Accepted Answer

The mean is sensitive to extreme scores (outliers), which can pull its value towards the extremes, unlike the median which is more robust to outliers.

Deck 11: The Mean: An Average