(begin{array}{c|c} x & 2 & 4 & 6 & 8\ hline f & 4 & y & 6 & 5 end{array})
If the mean of the above frequency distribution is 5.2, find y
If the mean of the above frequency distribution is 5.2, find y
-
A.
2, 1 -
B.
1, 2 -
C.
1, 5 -
D.
5, 2
Correct Answer: Option C
Explanation
Mean (bar{x}) = (frac{sum fx}{sum f})
= (frac{5.2}{1})
= (frac{8 + 4y + 36 + 40}{4 + y + 6 + 5})
= (frac{5.2}{1})
= (frac{84 + 4y}{15 + y})
= 5.2(15 + y)
= 84 + 4y
= 5.2 x 15 + 5.2y
= 84 + 4y
= 78 + 5.2y
= 84 = 4y
= 5.2y – 4y
= 84 – 78
1.2y = 6
y = (frac{6}{1.2})
= (frac{60}{12})
= 5