**Assignment – Descriptive Statistics and Graphic Data**

The objective of this assignment is to analyze data in order to model a population or process and make a conclusion. Students will utilize Minitab to create descriptive statistics and describe data graphically (dotplots, histogram, stem-and-leaf, and box plots). There are three parts of this assignment: 1) describing data graphically, 2) single boxplot, and 3) comparison boxplots. To earn high scores, students will complete all three parts; note that some sections asked you to calculate by hand. Submit your assignment in Word Document as a file attachment in Discussion Board, under forum “Assignment Three- Graphic Data”, see Course Schedule for the due date.

__Note__: The supplemental documents and data file in Minitab are located in Unit Two/Supplement, under folder “Minitab”.

1) To have Minitab on your computer, read the instruction for individual student licenses and

Free 30-day trial

2) Data file in Minitab for this assignment

3) Handout on how to create Dotplot, Histogram, Stem-and-Leaf and Boxplot and examples

**Part 1 – Describing data graphically **

Below are the ages at which the U.S. presidents began their first (non-consecutive) terms, increasing in order from George Washington to Barack Obama.

Presidents Ages (44 of them):

57

61

57

57

58

57

61

54

68

51

49

64

50

48

65

52

56

46

54

49

51

47

55

55

54

42

51

56

55

51

54

51

60

62

43

55

56

61

52

69

64

46

54

47

The data file is attached in this assignment folder, open it in Minitab and select the column C1, Presidents Ages. Then using Minitab to create graphs and answer the following questions:

1. Create a table of descriptive statistics, showing values of min., max, range, S.D., and average.

2. Construct a dotplot for a data set

3. Construct a histogram for a data set

4. Construct a stem-and-leaf plot for a data set

Also, student will construct a stem-and-leaf plot by hand. You can write it by hand, then scan it into your document, OR you can type it in Word Document.

5. Understand and interpret the graphs, shape, center, and skewness of a data set

The final product will include interpretation of data set (shape, center, and skewness), together with tables/diagrams from Minitab.

**Part 2 – Single Boxplot**

Below are the ages at which the U.S. presidents began their first (non-consecutive) terms, increasing in order from George Washington to Barack Obama.

Presidents Ages (44 of them):

57

61

57

57

58

57

61

54

68

51

49

64

50

48

65

52

56

46

54

49

51

47

55

55

54

42

51

56

55

51

54

51

60

62

43

55

56

61

52

69

64

46

54

47

Assignment:

1. By hand, calculate the following values of this data set

a. first quartile (Q1), second quartile (Q2), third quartile (Q3),

b. interquartile range (IQR).

c. then using IQR to calculate lower and upper fences

d. use the fences from above to determine the data values for the lower whisker endpoint, upper whisker endpoint, and outliers (if any).

In your answer, student will show formula and details of your calculation. You can write your details by hand, then scan it into your document, OR you can type it in Word Document.

2. By Minitab/descriptive statistics, calculate the five-number summary statistics (minimum, maximum, first quartile (Q1), second quartile (Q2), and third quartile (Q3)) for this data.

3. By Minitab construct a boxplot using the statistics from 1 & 2.

**Part 3 – Comparison Boxplots**

This part is to create the comparison boxplots of snowfall in Whoville and Grinchville between 1972 – 2013. The data file is attached in this assignment folder, open it in Minitab and select the column C5 and C6, Snowfall. Then using Minitab to creating graphs and answer the following questions:

1. Construct comparison boxplots of snowfall in Whoville and Grinchville

2. Calculate the five-number summary statistics (minimum, maximum, first quartile (Q1), second quartile (Q2), and third quartile (Q3)) for this data; Whoville and Grinchville. Then answer these questions:

a. Which town has more median snowfall for these 42 years?

b. Which town has greater variability snowfall for these 42 years?