91Ó°ÊÓ

The following data give the money (in dollars) spent on textbooks by 35 students during the \(2011-12\) academic year. \(\begin{array}{lllllllll}565 & 728 & 870 & 620 & 345 & 868 & 610 & 765 & 550 \\ 845 & 530 & 705 & 490 & 258 & 320 & 505 & 957 & 787 \\ 617 & 721 & 635 & 438 & 575 & 702 & 538 & 720 & 460 \\ 840 & 890 & 560 & 570 & 706 & 430 & 968 & 638 & \end{array}\) a. Prepare a stem-and-leaf display for these data using the last two digits as leaves. b. Condense the stem-and-leaf display by grouping the stems as \(2-4,5-6\), and \(7-9\).

The following data give the number of text messages sent on 40 randomly selected days during 2012 by a high school student: \(\begin{array}{llllllllll}32 & 33 & 33 & 34 & 35 & 36 & 37 & 37 & 37 & 37 \\\ 38 & 39 & 40 & 41 & 41 & 42 & 42 & 42 & 43 & 44 \\ 44 & 45 & 45 & 45 & 47 & 47 & 47 & 47 & 47 & 48 \\ 48 & 49 & 50 & 50 & 51 & 52 & 53 & 54 & 59 & 61\end{array}\) a. Construct a frequency distribution table. Take 32 as the lower limit of the first class and 6 as the class width. b. Calculate the relative frequency and percentage for each class. c. Construct a histogram for the frequency distribution of part a. d. On what percentage of these 40 days did this student send more than 44 text messages?

The following data give the amounts (in dollars) spent on refreshments by 30 spectators randomly selected from those who patronized the concession stands at a recent Major League Baseball game. \(\begin{array}{rrrrrrrr}4.95 & 27.99 & 8.00 & 5.80 & 4.50 & 2.99 & 4.85 & 6.00 \\ 9.00 & 15.75 & 9.50 & 3.05 & 5.65 & 21.00 & 16.60 & 18.00 \\ 21.77 & 12.35 & 7.75 & 10.45 & 3.85 & 28.45 & 8.35 & 17.70 \\ 19.50 & 11.65 & 11.45 & 3.00 & 6.55 & 16.50 & & \end{array}\) a. Construct a frequency distribution table using the less-than method to write classes. Take \(\$ 0\) as the lower boundary of the first class and \(\$ 6\) as the width of each class. b. Calculate the relative frequencies and percentages for all classes. c. Draw a histogram for the frequency distribution.