Answer:
option D) The percentage is at most 89%
Explanation:
mean, u = 45
standard deviation, s = 11
%age of members between 17 and 77 = ?
chebyshev's theorem = 1 - 1/k²
according to the question,
u + ks = 77 (the upper limit given to us)
u - ks = 17 (the lower limit given to us)
let's find k now,
u + ks = 77
45 + k(11) = 77
11k = 32
k = 32/11 = 2.909....
by substituting the value in the chebyshev's theorem,
1 - 1/(2.91)² = 1 - 1/8.4681
= 1 - .1181 = .8819
= 88.19% = 88%
thus, the percentage of gym members aged between 17 and 77 is at most 89%