Section 2.1: Frequency Distributions and their Graphs

(Note: Scatter plots will be revisited on Unit 8.)

1.The Young Republicans Club asked its members how many hours they had worked during the previous week in part-time jobs. The following datalists the number of hours spent working during the previous week.

6 6 6 4 6 6 9 8 7 3 7 8

6 7 6 7 7 6 6 8 6 7 8 4

a.From these data complete the frequency table below. Round the relative frequencies to three decimal places.

(References: example 1 and 2 page 41, end of section exercises 27, 28 page 51) (7 points)

b.Using Excel construct a frequency histogramfor the frequency table in part a. Use the midpoint as the horizontal axis and frequency [f] as the vertical axis. Copy the graph from Excel into the project Word document.

(References: example 3 page 44, end of section exercises 29 – 32 page 52) (3 points)

c. Using Excel construct a relative frequency histogram for the frequency table in part a. Use the midpoint as the horizontal axis and frequency [f] as the vertical axis. Copy the graph from Excel into the project Word document. (References: example 5 page 46, end of section exercises 33 – 36 page 52 – 53) (3 points)

Section 2.2: More Graphs and Displays

2. A research team studied the ages of patients who had heart attacks caused by smoking. The ages of 34 patients who suffered a heart attack are reported below.

29 30 36 41 45 50 57 61 28 50 66 58

60 38 36 47 40 32 58 46 61 40 55 32

61 56 45 46 62 66 38 40 40 27

Construct a Stem-and-Leaf Plot from these data with Key: 5 | 7 = 57.

(References: example 1 page 55, end of section exercises 17 – 20 page 63) (5 points)

3.A new DVD movie was rated by 900 reviewers. The follow data summarizes those ratings.

Rating Frequency Relative Frequency

Excellent 200

Good 360

Fair 290

Poor 50

Complete the table for Relative Frequency. Using Excel, construct a pie chartusing the relative frequency as the percent for each category. Round the relative frequencies to 3 decimal places. The wedges should be labeled with a descriptive label and a numeric label. Copy the graph from Excel into the project Word document.

(References: example 4 page 58, end of section exercises 23 – 24 page 64) (6 points)

Section 3.2: Measures of Central Tendency

Be sure to show your work so that partial credit may be awarded.

4. The Young Republicans Club asked its members how many hours they had worked during the previous week in part-time jobs. The following data lists the number of hours spent working during the previous week.

6 6 6 4 6 6 9 8 7 3 7 8

6 7 6 7 7 6 6 8 6 7 8 4

a.Calculate the meanfor these data. (Round to 2 decimal places)

(References: example 1 page 67, end of section exercises 17 -22 page 75) (5 points)

b.Determine the medianfor these data.

(References: example 2 and 3 page 68, end of section exercises 17 -22 page 75) (5 points)

Section 2.4: Measures of Variation

Be sure to show your work so that partial credit may be awarded.

5.IQ scores for seniors age 60 – 80 have a bell-shaped distribution with a mean of 100 and a standard deviationof 25. Use the Empirical Rule to find the percentage of seniors age 60 – 80 with IQ scores between 75 and 125.

(References: example 7 page 88, end of section exercises 29 – 34 page 95 – 96) (6 points) Empirical Rule is found on page 88.

See attached problems.

The solution provides step by step method for the calculation of descriptive statistics and the preparation of histogram and pie chart. Formula for the calculation and Interpretations of the results are also included.