Question

half the enterta on d) A retur in tha had re Servings of fruit per day FIGURE 1.14 The dstribution of fruit consumption in a sample of 74 seventeen-year-oid girts for Exercise 1.30 1.31 1Q test scores. Figure 1.15 is a stemplot of the 1Q test scores of 78 seventh-grade students in a rural mid western (a) Four students had low scores that might be considered ng ent outliers. Ignoring these, describe the shape, center, and variability of the remainder of the distribution. (b) We often read that IQ scores for large popula tions are centered at 100. What percent of these 78 students have scores above 100? 7 24 7 79 FIGURE The distribu January 19 ad. 8 69 9 01 33 9 677 8 10 0022333344 10 555 666777789 11 000 01 1 11 2222333 4 444 11 55688999 12 0033 44 12 677888 13 02 13 1.33 rs FIGURE 1.15 The distribution of scores for 78 seventh-grade students, for Exercise 1.31

Answer 1

This is the example of stem-leaf plot

In this, 7|2,4 indicates 72,74 Thus, range 70-74 contains 2 values (72,74)

Similarly, for subsequent rows we can find frequencies of the range as count of values in that row

Thus, the frequency distribution will look like:

Range	Frequency
70-74	2
75-79	2
80-84	0
85-89	2
90-94	4
95-99	4
100-104	10
105-109	12
110-114	19
115-119	8
120-124	6
125-129	6
130-134	2
135-139	1
Total	78

The students who have scored above 100

= (Adding rows from 110-114 till 135-139) - 2

= 10+12+19+8+6+6+2+1 - 2

= 62

(Row 100-104 contains two students with score 100 Thus, we have subtracted 2)

Thus, percentage of students who scored above 100

= 62/78 * 100 %

= 79.49%