Question

An annual marathon covers a route that has a distance of approximately 26 miles. Winning times for this marathon are all over 2 hours. The following data are the minutes over 2 hours for the winning male runners over two periods of 20 years each Earlier Period 10 15 13 16 19 20 15 22 22 23 10 17 18 15 6 9 13 14 12 18 Recent Period 9 10 9 811 9 7 10 7 9 14 9 877 9 14 87 9 (a) Make a stem-and-leaf display for the minutes over 2 hours of the winning times for the earlier period. Use two lines per stem. (Use the tens digit as the stem and the ones digit as the leaf. Enter NONE in any unused answer blanks. For more details, view How to Split a Stem.) Minutes Beyond 2 Hours Earlier Period 3 X (b) Make a stem-and-leaf display for the minutes over 2 hours of the winning times for the recent period. Use two lines per stem. (Use the tens digit as the stem and the ones digit as the leaf. Enter NONE in any unused answer blanks.) Minutes Beyond 2 Hours Recent Period (c) Compare the two distributions. How many times under 15 minutes are in each distribution? earlier period times

Answer 1

a)

Stem-and-Leaf Display
Stem unit:	10
0
0	6 9
1	0 0 2 3 3 4
1	5 5 5 6 7 8 8 9
2	0 2 2 3
2

b)

Stem-and-Leaf Display
Stem unit:	10
0
0	7 7 7 7 7 8 8 8 9 9 9 9 9 9 9
1	0 0 1 4 4
1
2
2

c) earlier period=8 times

recent period=20 times

Answer 2