Question

Older people often have a hard time finding work. AARP reported on the number of weeks it takes a worker aged 55 plus to find a job. The data on number of weeks spent searching for a job contained in the table below. 17 0 0 28 18 37 7 13 33 0 24 50 4 48 5 19 3 25 2 29 4 8 8 32 1 27 7 47 6 0
a. Provide a point estimate of the population mean number of weeks it takes a worker aged 55 plus to find a job. Round the answer to two decimal places.
( ) weeks
b. At 95% confidence, what is the margin of error? Round the answer to four decimal places. ( )
c. What is the 95% confidence interval estimate of the mean? Round the answers to two decimal places. ( , )
d. Find the skewness. Round the answer to four decimal places. ( )

Answer 1

a) We know that ,

point estimate of population mean is sample mean =

Where,

n = total number of observations in the data set = 30

	x	(x-mean)^2
	17	0.071111
	0	280.0044
	0	280.0044
	28	126.9378
	18	1.604444
	37	410.7378
	7	94.73778
	13	13.93778
	33	264.6044
	0	280.0044
	24	52.80444
	50	1106.671
	4	162.1378
	48	977.6044
	5	137.6711
	19	5.137778
	3	188.6044
	25	68.33778
	2	217.0711
	29	150.4711
	4	162.1378
	8	76.27111
	8	76.27111
	32	233.0711
	1	247.5378
	27	105.4044
	7	94.73778
	47	916.0711
	6	115.2044
	0	280.0044
Total	502	7125.867
mean	16.73333
sd	15.67544

point estimate of the population mean number of weeks it takes a worker aged 55 plus to find a job is
16.73 weeks

b)At 95% confidence, what is the margin of error is,

MOE = 5.8526

c)  95% confidence interval estimate of the mean,

We 95% confidant that the true population mean lies in interval ,

d) The skewness

	x	(x-mean)^3
	17	0.018963
	0	-4685.41
	0	-4685.41
	28	1430.166
	18	2.032296
	37	8324.286
	7	-922.114
	13	-52.0344
	33	4304.232
	0	-4685.41
	24	383.7123
	50	36815.26
	4	-2064.55
	48	30566.43
	5	-1615.34
	19	11.64563
	3	-2590.17
	25	564.9256
	2	-3198.18
	29	1845.779
	4	-2064.55
	8	-666.101
	8	-666.101
	32	3558.219
	1	-3894.59
	27	1082.152
	7	-922.114
	47	27726.42
	6	-1236.53
	0	-4685.41
Total	502	77981.26

Skewness is 0.6981