試題詳解

270. An industrial company provides health insurance to employees located at four different plants. Health insurance costs at each plant are independent of the costs at any other plant. Plant managers have calculated the following statistics:

  Calculate the standard deviation of total company health insurance costs.
(A) 1.4
(B) 2.1
(C) 2.9
(D) 5.5
(E) 6.3