The line plot shows the results of a survey of 10 boys and 10 girls about how many hours they spent reading for pleasure the pre
vious week. Select from the drop-down menus to complete each statement. The range . The mean . Two line plots one above the other, both are labeled from zero to twelve by ones. The top line plot is labeled Boys with four Xs over five and one X over zero, two, three, four, ten, and twelve. The bottom line plot is labeled Girls with three Xs above eight, two Xs above three and four, and one X above two, six and seven.
Boys: <span>four Xs over five and one X over zero, two, three, four, ten, and twelve. 5, 5, 5, 5, 0, 2, 3, 4, 10, 12 </span>→ 0, 2, 3, 4, 5, 5, 5, 5, 10, 12<span> mean: 5.1 range: 12
</span><span>Girls: three Xs above eight, two Xs above three and four, and one X above two, six and seven. 8, 8, 8, 3, 3, 4, 4, 2, 6, 7 </span>→ 2, 3, 3, 4, 4, 6, 7, 8, 8, 8 <span>mean: 5.3 range: 6
The boys have the higher range while the girls have the higher mean value.
E [x] = Expected value of X μ = average σ = standard deviation V (X) = Variance σ = (V(X)) ^ 0.5 E [X] = X * P (x) Assuming that the number of books purchased is a discrete random variable with mean μ = E [X] Then the variance of X can be written as V (X) = E [X-μ]^2 We started finding the average μ μ = 0 * 0.20 + 1 * 0.30 + 2 * 0.50 μ = 1.3 Once the average is found, we can calculate the value of the variance V (X) = 0.20 * (0-1.3) ^ 2 + 0.30 * (1-1.3) ^ 2 + 0.50 * (2-1.3) ^ 2 V (X) = 0.61 Now we know that from the variance the standard deviation can be obtained by doing: σ = (V (X)) ^ 0.5 Finally σ = 0.781