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Biostatistics

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A-108 ANSWERS TO ODD-NUMBERED EXERCISES<br />

Class<br />

Interval<br />

Frequency<br />

Cumulative<br />

Frequency<br />

Relative<br />

Frequency<br />

Cumulative<br />

Relative<br />

Frequency<br />

1.5–1.99 15 36 16.67 40.00<br />

2.0–2.49 45 81 50.00 90.00<br />

2.5–2.99 9 90 10.00 100.00<br />

(b) 40.0% (c) .7667 (d) 16.67% (e) 9 (f) 16.67%<br />

(g) 2.17, because it composes almost 25 percent of the data and is the most<br />

frequently occurring value in the data set. (h) Skewed to the left.<br />

2.3.3. (a)<br />

Class<br />

Interval Frequency<br />

Cumulative<br />

Frequency<br />

Relative<br />

Frequency<br />

Cumulative<br />

Relative<br />

Frequency<br />

20–24.99 2 2 0.069 6.90<br />

25–29.99 11 13 0.3793 44.83<br />

30–34.99 6 19 0.2069 65.52<br />

35–39.99 2 21 0.069 72.41<br />

40–44.99 5 26 0.1724 89.66<br />

45–49.99 2 28 0.069 96.55<br />

50–54.99 1 29 0.0345 100.00<br />

12<br />

Histogram of BMI<br />

12<br />

Frequency polygon of BMI<br />

10<br />

10<br />

Frequency<br />

8<br />

6<br />

4<br />

Frequency<br />

8<br />

6<br />

4<br />

2<br />

2<br />

0<br />

22.5 27.5 32.5 37.5 42.5 47.5 52.5<br />

BMI<br />

0<br />

17.5 27.5 37.5 47.5 57.5<br />

BMI<br />

(b) 44.83% (c) 24.14% (d) 34.48% (e) The data are right<br />

skewed (f) 21

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