The following table relates the number of objects f corresponding to a certain size x. What is the average size of an object?
\(\begin{array}{c|c} f & 1 & 2 & 3 & 4 & 5 \\ \hline x & 1 & 2 & 4 & 8 & 16\end{array}\)
A
\(\frac{31}{15}\)
B
\(\frac{31}{5}\)
C
\(\frac{129}{5}\)
D
\(\frac{43}{5}\)
E
\(\frac{16}{5}\)
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
F = 1, 2, 3, 4, 5
x = 1, 2, 4, 8, 16
fx = 1, 4, 12, 32, 80, 3f = 15
(average size) = \(\frac{\sum fx}{\sum f}\)
= \(\frac{129}{15}\)
= \(\frac{43}{5}\)
Source: Myschool Past Questions Archive (Record #32680)