The probabilities shown in the table below represent the estimate of sales for a new product.

Sales (Units).. Probability

0-200 .................15%

201-400............. 45%

401-600 .............25%

601-800............. 15%

What is the best estimate of the expected sales of the new product?

Answer (B) is correct.
The expected sales levels should be weighted by the individual
probabilities of their occurrence. The midpoint of each sales level is used
as the estimate for that level. Thus, sales are expected to be 380 units.
100 × 15% = 15
300 × 45% = 135
500 × 25% = 125
700 × 15% = 105
380