To find the necessary sample size for a given level of confidence and accuracy of measurement.
My mgr needs information. I need to determine if a new product is worth marketing. At least 85 percent of the public must express interest in the product and for those that do the average cost they are willing to pay must be at least $47.50.
I survey 50 potential consumers regarding their interest in the product, 34 express an interest in purchasing it. The maximum price each would be willing to pay is shown below.
|
Maximum Prices
|
|
47
|
62
|
46
|
|
43
|
53
|
34
|
|
54
|
45
|
35
|
|
65
|
36
|
32
|
|
54
|
45
|
31
|
|
34
|
36
|
25
|
|
38
|
37
|
56
|
|
35
|
43
|
65
|
|
43
|
48
|
54
|
|
37
|
46
|
65
|
|
54
|
42
|
47
|
|
63
|
|
|
How large should the sample be if I want to maintain a 95 percent level of confidence and suffer a maximum error of $2.00 in my estimate of the highest price consumers are willing to pay?