Elementary Statistics, Chapter 2, Unit 1, Homework Problems Questions and Correct Answers

Elementary Statistics, Chapter 2, Unit 1, Homework Problems Questions and Correct Answers Refer to the table summarizing service times (seconds) of dinners at a fast food restaurant. How many individuals are included in the summary? Is it possible to identify the exact values of all of the original service times? - Answer -48 individuals are included in the summary (add up all numbers in the frequency column) No. The data values in each class could take on any value between the class limits, inclusive. A frequency table of grades has five classes (A, B, C, D, F) with frequencies of 5, 10, 18, 5, and 3 respectively. Using percentages, what are the relative frequencies of the five classes? - Answer -(divide a frequency (like 5) by the sum of frequencies, 41 and then multiply that by 100.) 12.20%, 24.39%, 43.90%, 12.20%, 7.32% Heights of adult males are known to have a normal distribution. A researcher claims to have randomly selected adult males and measured their heights with the resulting relative frequency distribution as shown here. Identify two major flaws with these results. - Answer -The sum of the relative frequencies is 124%, but it should be 100%, which a small possible round-off error. All of the relative frequencies appear to be roughly the same. If they are from a normal distribution, they should start low, reach a maximum, and then decrease. Identify the lower class limits, upper class limits, class width, class midpoints, and class boundaries for the given frequency distribution. Also identify the number of individuals included in the summary. Age (yr) when award was won: 25-34, 35-44, 45-54, 55-64, 65-74, 75-84, 85-94 Frequency: 29, 34, 16, 3, 5, 1, 2 - Answer -lower class limits: 25, 35, 45, 55, 65, 75, 85 upper class limits: 34, 44, 54, 64, 74, 84, 94 class width: 10 (34-25+1)