IMPORTANT PART A AND PART B ARE DONE, THE ANSWERS ARE BELOW THE QUESTIONS , I ON
ID: 2947626 • Letter: I
Question
IMPORTANT PART A AND PART B ARE DONE, THE ANSWERS ARE BELOW THE QUESTIONS , I ONLY NEED HELP WITH PART C PLEASE 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. A study 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 diastolic blood pressures obtained prior to intervention for a random sample of 25 bus drivers in the study 79 83 85 63 74 75 65 90 90 89 93 93 79 73 95 70 95 80 73 83 94 Summarize the data using a steam and leaf display, summarize the data using a histogram with 5 classes, construct a boxplot and use it to investigate the data for outliers and summarize the data set using the sample mean, median, and standard deviations Construct a normal probability plot of quantile-quantile(QQ) plot to assess normality. Use this assessment to determine which procedures are appropriate for these data for confidence interval and test of the hypothesis. Construct a 90% confidence interval for u, the population mean diastolic blood pressure of all urban bus drivers in Stockholm. In adults the ideal diastolic blood pressure is 80 mm Hg. At the 10% 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, perfornm the full hypothesis test. a) b) c) Compare the measures of center and comment on the shape of the distribution. Include results of investigation for outliers, Assess normality. Write an interpretation for the interval estimate using the context of the data. State the conclusions of the significance test and interpret the p-value using the context of the data. Compare the results from the confidence interval and the significance test. Are they the same? Why do think this is the case?Explanation / Answer
Answer C
Measure of center are given below
mean = 82.800, median =83 and mode = 81
Shape of the distribution is almost normal because the mode, median and mean are very close to each other. If we look at the box plot, then it is clear that there is no outlier present in the data.
90% confidence interval is (79.4401, 86.1599) which contains the hypothesized value of mean 80mmHg, thus we can say that the confidence interval hypothesis test contains the null value of mean, i.e. we fail to reject the null hypothesis.
P value for t test hypothesis is 0.0864 which is less than 0.10, so we can say that at 90% significance level, we have enoughe evidence to conclude that the mean DBP of bus drivers is more than 80mmHg.
The result from the t test hypothesis and confidence interval are opposite to each other. This difference is just because of the 0.10 alpha level as we know that if we have used 0.05 alpha level instead of 0.10 then confidence interval will also give the same result as that of t test.