Question

Find the quartile deviation of the following discrete series.
`{:(x,8,10,13,16,19,22),(f,4,7,8,3,5,4):}`
A. 3.5
B. 6
C. 5
D. 4.5

Answer 1

Correct Answer - D
`{:(x,f,"Less than cumulative"),(,," ""Frequency"),(8,4," "4),(10,7," "11),(13,8," "19),(16,3," "22),(19,5," "27),(22,4," "31):}`
N = 31
`Q_(1)` = size of `((n + 1))/(4)`th item = 8th item = 10.
`Q_(3)` = size of `(3(n + 1))/(4)`th item = 24th item = 19.
`QD = (Q_(3) - Q_(1))/(2) = (19-10)/(2) = 4.5`.