# math241 statics

**question:** Previous studies have shown that urban bus drivers have an extremely stressful job, and a large proportion of drivers retire prematurely with disabilities due to occupational stress. These stresses come from a combination of physical and social sources such as traffic congestion, incessant time pressure, and unruly passengers. In the paper, â€œHassles on the Job: A Study of a Job Intervention with Urban Bus Driversâ€ (*Journal of Organizational Behavior*, Vol. 20, pp. 199 â€“ 208), G. Evans et al. examined the effects of an intervention program to improve the conditions of urban bus drivers. Among other variables, the researchers monitored diastolic blood pressure of bus drivers in downtown Stockholm, Sweden. The data, in millimeters of mercury (mm Hg), are based on the blood pressures obtained prior to intervention for the 41 bus drivers in the study.

**A) ****Exploratory Data Analysis**

a. Summarize the data using aâ€¦

i. stem and leaf diagram.

ii. histogram with approximately 7 classes.

1. Use class limits on the horizontal axis.

2. Use frequencies on the vertical axis.

3. Show class frequency on top of bars.

iii. box and whiskers plot.

b. Investigate the data for definite outliers. Drop all definite outliers from the set and redo part a.

c. Summarize the data set using a table of descriptive statistics. The table must be generated by a **statistical software **and include the following statistics:

i. The number of observations in data set

ii. Mean

iii. Median

iv. Mode

v. Max

vi. Min

vii. Quartiles

viii. Interquartile range

ix. Standard deviation

x. Variance

xi. Range

xii. Standard error of the mean

**B) ****Inferential Statistics**

a. Use a **STATISTICAL SOFTWARE** to construct a 90% confidence interval for Âµ, the population mean diastolic blood pressure of all urban bus drivers in Stockholm.

b. In adults the ideal diastolic blood pressure is 80 mm Hg. At the 5% significance level, do the data provide sufficient evidence to conclude that the mean diastolic blood pressure of bus drivers in Stockholm exceeds the normal diastolic blood pressure of 80 mm Hg? Have **Software** conduct the appropriate test. Using the **software **output, perform the full hypothesis test.

** **

**C) ****Project Summary & Findings **

a. Write a brief introductory paragraph regarding the background of data.

b. Write paragraph (or two) that specifies the shape of the distribution of the data and reference your graph(s) used to make your decision.

c. Discuss the presence or absence of outliers.

d. Interpret the following values within context for the sample mean, median, and mode.

e. State the range of the data and the standard deviation.

f. State the practical interpretation for the 90% confidence interval.

g. State the null hypothesis, the test-statistic, and the p-value for the hypothesis test in **B)**.

h. Clearly state your conclusions of the hypothesis test within context and include the significance level in your statement.

D) Format for submitting Statistics Project Option B

a. First â€“ page: Title page with appropriate project title, name, course number and section number. (The title page must be typed.)

b. Part **C)**

c. Division Page for â€œMETHODSâ€

d. Part **A) **â€“ include all **software **Output.

e. Part **B) **â€“ include all **software **Output.

f. How has this project helped you understand the purpose and value of the study of statistics? Your response must be in complete sentences and may be handwritten.