Question

MTH 241 COMMON DATA ANALYSIS ASSIGNMENT

(Fall 2018)

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, “Hassles on the Job: A Study of a Job Intervention with Urban Bus Drivers” (Journal of Organizational Behavior, Vol. 20, pp. 199 – 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 30 bus drivers in the study. See data below.

SHOW WORK USING StatCrunch !

89	99	80	95	83	63	90	90	93	91
79	84	81	100	81	90	89	94	85	76
77	80	65	73	73	70	81	75	74	83

A. Write a brief introductory paragraph regarding the background of data and the purpose of investigation.

B. Exploratory Data Analysis

a. Summarize the data using a…

1. stem and leaf diagram.

2. histogram.

-Use a class width of 10 mm Hg.

-Start with a class limit of 60 mm HG.

-Use frequencies on the vertical axis.

-Show class frequency on top of bars.

3. 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 (such as StatCrunch) and include the following statistics:

The number of observations in data set

Mean

Median

Mode

Max

Min

Quartiles

Interquartile range

Standard deviation

Variance

Range

Standard error of the mean

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

e. Interpret the numerical values obtained in part c.

C.Inferential Statistics

a. Use a STATISTICAL SOFTWARE to construct a 95% confidence interval for µ, the population mean diastolic blood pressure of all urban bus drivers in Stockholm.

b. In adults the ideal diastolic blood pressure is less than 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 79 mm Hg? Have Software conduct the appropriate test. Using the software output, perform the full hypothesis test.

c. Are the results of the confidence interval and hypothesis test the same? Explain why or why not.

d. Summarize your investigation in part b. and make a recommendation that is based on your statistical analysis.

D.Project Summary & Findings

State the practical interpretation for the 95% confidence interval.

State the null hypothesis, the test-statistic, and the p-value for the hypothesis test in C).

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

E.Formatting the Document to Submit

SHOW WORK USING StatCrunch !

Cover Page: Project title, name, course number and section number.

Part A) in a single paragraph.

Part B) – Describe the data set. Include all software output (graphs and tables) embedded within or between the paragraphs that describe the data. DO NOT ATTACH THE SOFTWARE OUTPUTS AT THE END OF YOUR DOCUMENT!!

Part C) – Write the paragraphs that describe the purpose and method of the investigation outlined in this part. Discuss the results generated from StatCrunch. Insert all software outputs near the sentences where they are being talked about. DO NOT ATTACH THE SOFTWARE OUTPUTS AT THE END OF YOUR      DOCUMENT!!

Part D) - Write your concluding paragraph(s) and make sure to include the three items listed in this part.

Rubrics

Part A.               5 points

Part B.             23 points

Part C.             22 points

Part D.             10 points

Answer 1

C) inferential statistics

Confidence intervals are interval estimates for the population characteristics ( Here it is mean of the population.If a sampling is done from the same population 100 times and the population mean are estimated from each sample then 95 of the resulting confidence intervals will contain the true population mean. so at 5% level of significance the population mean is greater than 79.4044

Null and alternative hypothesis are and  

Which implies there is enough evidence from the sample to conclude at 5% level of significance that the  normal diastolic blood pressure of the population is greater than 79 mm Hg

So the conclusion from the hypothesis testing and confidence interval calculation are the same. so it makes sure the fact that urban bus drivers have an extremely stressful job, and a large proportion of drivers retire prematurely with disabilities due to occupational stress.  so remedial measures need to be taken to reduce their work stress.