Question

a. Of all students at the University of Metropolis, the proportions taking certain numbers of units are as shown in the table below.

Units	3	4	5	6	7	8
Proportion	2%	4%	5%	7%	5%	4%

Units	9	10	11	12	13	14
Proportion	8%	10%	13%	13%	17%	12%

Find the expected number of units that a student at U.M. takes. (Enter your answer to two decimal places.)
units in $

b. On the basis of his sale records, a salesman knows that his weekly commissions have the probabilities shown below.

Commission	0	$1,000	$2,000	$3,000	$4,000
Probability	0.11	0.2	0.49	0.1	0.1

Find the salesman's expected commission.
$

Answer 1