Answer:
0.438
Step-by-step explanation:
Given the data:
980.9, 1036.5, 1099.5, 1153.9, 1409.0, 1456.4, 1718.4, 1721.2
Coefficient of skewness:
3 * (mean - median) / standard deviation
The mean of the dataset :
Σ(X) / N ; N = sample size = 8
980.9+1036.5+1099.5+1153.9+1409.0+1456.4+1718.4+1721.2
= 10575.8 / 8
= 1321.975
Median :
980.9, 1036.5, 1099.5, 1153.9, 1409.0, 1456.4, 1718.4, 1721.2
1/2(n + 1)th term
1/2(9) = 4.5th term
(1153.9+1409.0) / 2
= 1281.45
Standard deviation:
Sqrt[Σ(X - mean)²/ (N - 1)]
Using calculator :
Standard deviation estimate of population = 277.882456
Coefficient of skewness :
3(1321.975 - 1281.45) / 277.882456
121.575 / 277.882456
= 0.4375051
= 0.4375
Using software excel :
Using excel's AVERAGE, MEDIAN and STDEV.P functions, the Coefficient of skewness can be obtained using the formula :
3 * (mean - median) / standard deviation
Coefficient of skewness obtained is 0.438
