Some sales representatives want to determine which approach would result in more sales for a manufacturing product. The three approaches are
- videotaped information mailed on CD to prospective customers,
- a face-to-face visit to prospective customers, or
- a telephone call to prospective customers.
A random sample of 300 prospective customers was selected with 100 assigned to each of the three different sales approaches. The results are tabulated below:
|
Sales approach
|
|
|
Videotape
|
Person sales visit
|
Phone call
|
Total
|
|
Purchase
|
19
|
27
|
14
|
60
|
|
Didn't purchase
|
81
|
73
|
86
|
240
|
|
Total
|
100
|
100
|
100
|
300
|
Test if the purchase behaviour is independent of the sales approach at the significance level of 0.05, by answering the following.
(a) State your two hypotheses
(b) Calculate the test statistic
(c) Quote a critical value from Tables. Is your test significant? State your conclusion in plain English.
(d) Regardless of your answer in (c), which cell makes the biggest contribution to the test statistic?