## Write a statistical report based on the sample of 50 freight trains in United States.

Write a statistical report based on the sample of 50 freight trains in the United States

have an introduction part that provides brief background information on the freight trains. Then start to present your sample results to cover all topics listed below. You should present all results in a logical and organized way. A list of numbers and charts will not earn high scores.

(1) A stem-and-leaf plot (with proper keys) to present all sample data

(2) A bar graph to summarize the sample data by display a frequency distribution (with proper classes and details)

(3) Centers of the sample data mean and median: discuss in general what they measure and what example results show.

(4) Measure the variation of the sample data standard deviation and range: discuss in general what they measure and what example results show.

(5) Discuss if there are any outliers in the sample in a quantitative way (e.g. IQR measure).

(6) Explain the meaning of confidence interval for a population mean and present the 90%-confidence interval from this sample.

In the end, use a paragraph to close the report.