Question

1. select all the statements that are true about standard deviation. a. it is a measure of center. b. it is a measure of variability. c. it tells you the minimum and maximum values d. it is calculated using the median. 12. a set of data has ten numbers. the mean of the data is 12 and the standard deviation is 0. if you were to choose 3 numbers from that set of data, what would they be? explain your reasoning. 13. the number of letters received in the mail over the past week is recorded. 2 3 5 5 5 15 which value appears to be an outlier? a. 2 b. 3 c. 5 d. 15

Explanation:

11.

Step1: Recall standard - deviation concept

Standard deviation measures how spread out the data is, which is a measure of variability. Mean, median and mode are measures of center. Standard deviation is calculated using the mean, not the median, and it does not tell the minimum and maximum values.

Step1: Understand the meaning of standard - deviation = 0

A standard deviation of 0 means that all the data points in the set are the same. Since the mean of the data set of ten numbers is 12, all the numbers in the set are 12. So any three numbers chosen from the set will be 12, 12, 12 because when the standard deviation is 0, there is no variability and all values equal the mean.

Step1: Identify the outlier concept

An outlier is a data point that is significantly different from the other data points. In the data set {2, 3, 5, 5, 5, 15}, most of the values are around 2 - 5, while 15 is much larger.

Answer:

B. It is a measure of variability.

12.