Question

Health insurers are beginning to offer telemedicine services online that replace the common offi­ce visit. Wellpoint provides a video service that allows subscribers to connect with a physician online and receive prescribed treatments. Wellpoint claims that users of its LiveHealth Online service saved a signi­ficant amount of money on a typical visit. The data shown below ($), for a sample of 20 online doctor visits, are consistent with the savings per visit reported by Wellpoint.

92 34 40 (92,34,40)

105 83 55(105,83,55)

56 46 40(56,46,40)

76 48 96(76,48,96)

93 74 73(93,74,73)

78 93 100(78,93,100)

53 80 (53,80)

Assuming that the population is roughly symmetric, construct a 95% confi­dence interval for the mean savings for a televisit to the doctor as opposed to an of­fice visit.

Answer 1

Here sample mean is

To find standard deviation

Create the following table.

data	data-mean	(data - mean)2
92	21.25	451.5625
34	-36.75	1350.5625
40	-30.75	945.5625
105	34.25	1173.0625
83	12.25	150.0625
55	-15.75	248.0625
56	-14.75	217.5625
46	-24.75	612.5625
40	-30.75	945.5625
76	5.25	27.5625
48	-22.75	517.5625
96	25.25	637.5625
93	22.25	495.0625
74	3.25	10.5625
73	2.25	5.0625
78	7.25	52.5625
93	22.25	495.0625
100	29.25	855.5625
53	-17.75	315.0625
80	9.25	85.5625

Find the sum of numbers in the last column to get.

So

t table value for n=20, 95% CI is 2.093

Hence Margin of Error is

Hence CI is