Question 19 asks whether quartiles, percentiles, and deciles divide a data set into equal groups. Question 20 asks whether variance and standard deviation measure the dispersion or spread of a data set.

1. Problem Description

Question 19 asks whether quartiles, percentiles, and deciles divide a data set into equal groups. Question 20 asks whether variance and standard deviation measure the dispersion or spread of a data set.

2. Solution Steps

Question 19:

Quartiles divide a data set into four equal groups (quarters). Percentiles divide a data set into one hundred equal groups (hundredths). Deciles divide a data set into ten equal groups (tenths). Therefore, quartiles, percentiles, and deciles do divide a data set into equal groups. The statement is true.

Question 20:

Variance and standard deviation are statistical measures that quantify the amount of dispersion or spread in a data set. They indicate how far individual data points are from the mean or average value. Thus, the statement is true.

3. Final Answer

Question 19: A. True

Question 20: B. True