Find the unknown entries a, b, c, d, e, f in the following distribution of heights of students in a class :
Height (in cm) | Frequency | Cumulative frequency |
150-155 155-160 160-165 165-170 170-175 175-180 |
12 b 10 d e 2 |
a 25 c 43 48 f |
Total | 50 |
Solution. Frequency distribution: It tells how frequencies are distributed overvalues in a frequency distribution. However mostly we use frequency distribution to
summarize categorical variables.
( because first term of frequency and cumulative frequency is same )
12 + b = 25
b = 25 – 12
b = 13
25 + 10 = c
35= c
c + d = 43
35 + d = 43
d = 43 – 35
d=8
43 + e = 48
e = 48 – 43
e =5
48+2 = f
50 = f
Ans. a = 12, b = 13, c = 35, d = 8, e = 5, f = 50