Question

Consumer Banker Association released a report showing the lengths of automobile leases for new automobiles. The results are as follows. Lease Length in Months Percent of Leases 13-24 25-36 37-48 49-60 More than 60 11.8% 36.4% 25.3% 26.1% 0.4% (a) Use the midpoint of each class, and call the midpoint of the last class 66.5 months, for purposes of computing the expected lease term. Also find the standard deviation of the distribution. (Round your answers to two decimal places.) expected lease term months standard deviation (b) Sketch a graph of the probability distribution for the duration of new auto leases. Maple Generated Plot Maple Generated Plot Maple Generated Plot Maple Generated Plot

Answer 1

Solution:-

a)

Class interval	Percent lease	Mid-point
13 to 24	11.80%	18.5
25 to 36	36.40%	30.5
37 to 48	25.30%	42.5
49 to 60	26.10%	54.5
More than 60	0.40%	66.5
Total	100.00%

Class interval	Mid-point (x)	Percent lease(P(x)	x*P(x)	(x - u)^2	P(x)*(x - u)^2
13 to 24	18.5	0.118	2.183	401.1208	47.33225251
25 to 36	30.5	0.364	11.102	64.44878	23.45935738
37 to 48	42.5	0.253	10.7525	15.77678	3.991526352
49 to 60	54.5	0.261	14.2245	255.1048	66.58234862
More than 60	66.5	0.004	0.266	782.4328	3.129731136
Total		1	38.528	1518.884	144.495216

b)