Consider the following distribution: Class | Frequency; 0–20 | 17; 20–40 | 28; 40–60 | 32; 60–80 | f; 80–100 | 19. If the mean of the above distribution is 50, what is the value of f ?

CDS 2017 PYQ with Answer — Consider the following distribution: Class | Frequency; 0–20 | 17; 20…

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2017 · Q53

Consider the following distribution:

Class	Frequency
0–20	17
20–40	28
40–60	32
60–80	f
80–100	19

If the mean of the above distribution is 50, what is the value of f ?

Elementary MathematicsStatistics

Explanation

With midpoints 10, 30, 50, 70, 90: (17×10 + 28×30 + 32×50 + 19×90 + 70f)/(96 + f) = 50. So 4320 + 70f = 4800 + 50f, giving 20f = 480 and f = 24: option A.