Measures of dispersion

Dispersion measures will be used. Compute measures of dispersion for populations and samples, for both ungrouped and grouped data. Present the processes necessary to support the answers to the exercises and round the final resultsnot the intermediate values that appear during calculationsto two decimal places, when necessary.

1) Why is the standard deviation considered one of the best measures to determine the variation between the data?

2) A nutritionist obtains the amounts of sugar (grams) for 10 different cereals, including Cheerios, Corn Flakes, Froot Loops, and seven others. The amounts appear below: 3, 24, 30, 47, 43, 7, 47, 13, 44, 39. Calculate the standard deviation of the amount of cereal sugar consumed by the population of all Puerto Ricans who eat cereal (Triola , 2004).

3) The monthly salary of five (5) employees of a pharmaceutical company was the following: $3,667, $4,935, $3,876, $4,700 and $3,178. What should be the value of the standard deviation for these data?

4) The waiting times of eight (8) patients to be seen in a medical office, expressed in minutes, were the following: 34, 56, 48, 29, 33, 44, 51, 65. Calculate the following: range, variance and standard deviation.

5) The ages of the 10 best actresses in Hollywood are as follows: 37, 48, 56, 66, 55, 60, 52, 54, 48, 69. Use the 10 ages of the best actresses to calculate the interquartile range.

6) Use the following sample data to calculate the coefficient of variation for each sample; then compare the results. Weight of NUC University students of both sexes: 132, 185, 167, 220, 155, 141, 150. Size in inches of babies at birth: 12, 15.3, 11, 10, 16, 13.5, 14.8

7) The presented frequency distribution describes the speed at which some young people drove to get to take their classes at the university. These young people were driving on a highway with a speed limit of 35 mi/h. Calculate the variance and standard deviation.

Speed Frequency 42-45 20 46-49 13 50-53 8 54-57 4 58-61 3

8) The following sample data are presented: 1.8, 1.9, 1.8, 2.4, 5.1, 3.1, 5.5, 5.1, 8.3, 13.7, 5.3, 4.9, 3.7, 3.8, 9.8. Calculate the following:

a) average b) fashion c) median d) middle axis e) range f) variance g) standard deviation