Question

Select THREE facts about standard deviations.

a. They are inferential statistical tools.
b. They are the most widely used measures of variability.
c. They are computed by dividing the mean by the number of scores.
d. Psychologists only use them when statistical reliability is greater than 99%.
e. They are arbitrary computations that create simple numbers representing how close a score is to the mean.
f. Standard deviations less than –3 or greater than 3 are unusual because they represent less than 1% of all scores.

Answer 1

The standard deviation is a measure of variability in a data set, and it tells us how the data values are spread out from the mean. Standard deviations are the most widely used measures of variability, less than -3 or greater than 3 standard deviations are considered unusual, and the standard deviation is computed by taking the square root of the variance.

Step-by-step explanation:

The standard deviation is a measure of variability in a data set. It provides information about how the data values are spread out from the mean. Here are three facts about standard deviations:

1. They are the most widely used measures of variability. The standard deviation is commonly used to describe the spread of data in various fields.
2. Standard deviations less than -3 or greater than 3 are unusual. When a data value is more than 3 standard deviations away from the mean, it is considered an outlier and represents less than 1% of all scores.
3. The standard deviation is computed by dividing the mean by the number of scores. This is not accurate. The standard deviation is actually calculated by taking the square root of the variance, which is calculated by subtracting each data value from the mean, squaring the differences, summing them, and dividing by the number of scores.