# distribution table, histogram, stem-and-leaf plot, etc.

1.) A researcher has been measuring the time for pairs of 8 year olds who have just met each other to work together to solve a problem. Using the following set of times to first disagreement (minutes) for each pair to answer the following questions:

scores: 30, 33, 40, 37, 32, 33, 40, 41, 34, 40, 31, 34, 34, 39, 37, 40, 35, 41, 41, 40.

a. Construct a distribution table for these data. include the colums and values for proportion and percentage.

b. Construct a frequency distribution histogram graph for the data.

c. Construct a stem and leaf plot for these data.

2.) Dr. I.C. Ewe has collected reaction times (in seconds) for an eye tracking test with individuals who have been given an experimental drug. your job is to organize the data for Dr. EWE.

Reaction times: 15, 51, 59, 41, 43, 33, 64, 78, 46, 38, 52, 47, 57, 54, 41, 20, 66, 45, 32, 37.

a. Construct a frequency distribution table for these data. Be sure to explain your selection of a tabular vs. grouped distribution table. Include in your table columns for proportion and percent.

b. Draw graph of these data. Be sure to explain your selection of the type of graph you use.

c. Construct a table with cf and c%

d. What scores has a percential rank of 60%?

e. What score has a percentile rank of 50%?

f. What is the percentile rank for X= 45?

g. What is the percentile rank for X= 32?

#### Solution Preview

1.) A researcher has been measuring the time for pairs of 8 year olds who have just met each other to work together to solve a problem. Using the following set of times to first disagreement (minutes) for each pair to answer the following questions:

scores: 30, 33, 40, 37, 32, 33, 40, 41, 34, 40, 31, 34, 34, 39, 37, 40, 35, 41, 41, 40.

To make everything easier, I'm going to sort the scores from lowest to highest:

30

31

32

33

33

34

34

34

35

37

37

39

40

40

40

40

40

41

41

41

a. Construct a distribution table for these data. include the colums and values for proportion and percentage.

The distribution table is below. The scores range from 30 to 41, so I included those numbers as possible values in the first column. The frequency is how often they appear in your list of scores. There are 20 scores, in the list, so we take the frequency divided by 20 to find the proportion and percentage.

Number of Minutes Frequency Proportion Percentage

30 1 1/20 = 0.05 5%

31 1 1/20 = 0.05 5%

32 1 1/20 = 0.05 5%

33 2 2/20 = 0.10 10%

34 3 3/20 = 0.15 15%

35 1 1/20 = 0.05 5%

36 0 0 0%

37 2 2/20 = ...

#### Solution Summary

The solution shows how to make a distribution table (with relative and absolute frequencies), a histogram, and a stem-and-leaf plot. It also shows how to calculate percentile ranks.