Question

Jobs for the homeless! A philanthropic foundation bought a used school bus that stops at homeless shelters early every weekday morning. The bus picks up people looking for temporary, unskilled day jobs. The bus delivers these people to a work center and later picks them up after work. The bus can hold 139 people, and it fills up every morning. Not everyone finds work, so at 11 A.M. the bus goes to a soup kitchen where those not finding work that day volunteer their time. Let us view each person on the bus looking for work as a binomial trial. Success means he or she got a day job. The random variable r represents the number who got jobs. The foundation requested a P-Chart for the success ratios. For the past 3 weeks, we have the following data.

Day	1	2	3	4	5	6	7	8
r	60	53	61	66	67	55	53	58
p̂ = r / 139	0.43	0.38	0.44	0.47	0.48	0.40	0.38	0.42

Day	9	10	11	12	13	14	15
r	60	52	46	52	61	70	58
p̂ = r / 139	0.43	0.37	0.33	0.37	0.44	0.50	0.42

Make a P-Chart. (Use 4 decimal places.)

Center line	=
–2.0 SL	=
2.0 SL	=
–3.0 SL	=
3.0 SL	=

List any out-of-control signals by type (I, II, or III). (Select all that apply.)

Out-of-control signal I occurs on day 11.Out-of-control signal I occurs on day 14.Out-of-control signal III occurs on days 4 and 5.Out-of-control signal III occurs on days 14 and 15.There are no out-of-control signals.

Interpret the results.

Answer 1