Answer: V(X) = 0.96
Step-by-step explanation: <u>Variance</u> is defined as the average of the squared difference from the sample or population mean.
For a discrete frequency distribution is calculated following the steps:
1) Determine expected value or mean:
E(X) = 1.2
2) Multiply frequency and the squared difference of x and expected value:
3) Add them:
= 1008 + 36 + 384 + 972 = 2400
4) Divide the sum per frequency total:
V(X) = 0.96
The variance of the number of cups of coffee is <u>0.96</u>.