Final answer:
The standard deviation is 111.64 and its coefficient is 2.791%.
Step-by-step explanation:
a) To find the standard deviation, we can use the formula: Standard Deviation = sqrt(Var) where Var is the variance.
The formula for variance is: Var = (Sum of (x - mean)^2) / n
First, let's calculate the mean:
mean = e*f = 200 * 20
= 4000.
Next, let's calculate the variance:
Var = [(200^2 * 20) + (3280 - 4000)^2] / (20 + 1)
= 262160 / 21
= 12484.762.
Finally, the standard deviation is:
Standard Deviation = sqrt(12484.762)
= 111.64.
b) To calculate the coefficient of standard deviation, we can use the formula:
Coefficient of Standard Deviation = (Standard Deviation / Mean) * 100.
Plug in the values:
Coefficient of Standard Deviation
= (111.64 / 4000) * 100
= 2.791%.