A sample of 26 offshore oil workers took part in a simulated escape exercise, resulting in the accompanying data on time (sec) to complete the escape (“Oxygen Consumption and Ventilation During Escape from an Offshore Platform,” Ergonomics, 1997: 281–292): a. ?Construct a stem-and-leaf display of the data. How does it suggest that the sample mean and median will compare? b.? ?Calculate the values of the sample mean and median. c. By how much could the largest time, currently 424, be increased without affecting the value of the sample median? By how much could this value be decreased without affecting the value of the sample median? d. What are the values of the observations are reexpressed in minutes?

Solution : Step 1 : The given data is a sample of 6 offshore oil workers took part in a simulated escape exercise, resulting in the accompanying data on time (sec) to complete the escape. 389 356 359 363 375 424 325 394 402 373 373 370 364 366 364 325 339 393 392 369 374 359 356 403 334 397 Step 2 : a) We have to make a stem-Leaf graph for the given observations. And also want to know the nature of mean and median. 1)In order to make the stem-Leaf display first we have to arrange the data in ascending order. Here it will be 325 325 334 339 356 356 359 359 363 364 364 366 369 370 373 373 374 375 389 392 393 394 397 402 403 424 2) By considering the ten digit as Stem and one digit as Leaf we will get the Stem-Leaf display as: From the display it is clear that the data is reasonably symmetric. So the mean and median will be close value.