Answer: 100 %
Explanation:
The first step is to rearrange the numbes in ascending order. It becomes
56, 57, 57, 57, 58, 62, 88, 92
The next step is to calculate the population μ, mean.
μ = sum of terms/number of terms
From the information given
n = number of terms = 8
μ = (56 + 57 + 57 + 57 + 58 + 62 + 88 + 92)/8 = 65.875
μ = 65.875
The formula for calculating the population standard deviation, σ is
σ = √[Σ(x - μ)^2]/n
Σ(x - μ)^2/n = [(56 - 65.875)^2 + (57 - 65.875)^2 + (57 - 65.875)^2 + (57 - 65.875)^2 + (58 - 65.875)^2 + (62 - 65.875)^2 + (88 - 65.875)^2 + (92 - 65.875)^2)]/8 = 197.859375
σ = √197.859375
σ = 14.1
2 population standard deviations to the left of the mean = 65.875 - 2(14.1) = 37.675
2 population standard deviations to the rig tof the mean = 685875 -+2(14.1) == 94.075
Number of terms between 37.675 and 94.075 = 8
Thus,
the percentage of data within 2 population standard deviations of the mean
= 8/8 x 100 = 100%
