In: Statistics and Probability
The owner of a restaurant that serves Continental-style entrées has the business objective of learning more about the patterns of patron demand during the Friday-to-Sunday weekend time period. She decided to study the i.) demand for dessert during this time period, ii.) the gender of the individual, and iii.) whether or not a beef entrée was ordered. Data were collected from 630 customers and organized in the following contingency tables:
Gender
| Dessert Ordered | Male | Female | Total |
| Yes | 50 | 96 | 146 |
| No | 250 | 234 | 484 |
| Total | 300 | 330 | 630 |
Beef Entree
| Dessert Ordered | Yes | No | Total |
| Yes | 74 | 68 | 142 |
| No | 123 | 365 | 488 |
| Total | 197 | 433 | 630 |
1. At the a = 0.05 level of significance, is there evidence of a difference between males and females in the proportion who order dessert?
2. At the a = 0.05 level of significance, is there evidence of a difference in the proportion who order dessert based on whether a beef entrée was ordered?
1. The hypothesis being tested is:
H0: p1 = p2
Ha: p1 ≠ p2
| p1 | p2 | pc | |
| 0.1667 | 0.2909 | 0.2317 | p (as decimal) |
| 50/300 | 96/330 | 146/630 | p (as fraction) |
| 50. | 96. | 146. | X |
| 300 | 330 | 630 | n |
| -0.1242 | difference | ||
| 0. | hypothesized difference | ||
| 0.0337 | std. error | ||
| -3.69 | z | ||
| .0002 | p-value (two-tailed) |
The p-value is 0.0002.
Since the p-value (0.0002) is less than the significance level (0.05), we can reject the null hypothesis.
Therefore, we can conclude that there is a difference between males and females in the proportion who order dessert.
2. The hypothesis being tested is:
H0: p1 = p2
Ha: p1 ≠ p2
| p1 | p2 | pc | |
| 0.3756 | 0.157 | 0.2254 | p (as decimal) |
| 74/197 | 68/433 | 142/630 | p (as fraction) |
| 74. | 68. | 142. | X |
| 197 | 433 | 630 | n |
| 0.2186 | difference | ||
| 0. | hypothesized difference | ||
| 0.0359 | std. error | ||
| 6.09 | z | ||
| 1.15E-09 | p-value (two-tailed) |
The p-value is 0.0000.
Since the p-value (0.0000) is less than the significance level (0.05), we can reject the null hypothesis.
Therefore, we can conclude that there is a difference between males and females in the proportion who order dessert based on whether a beef entrée was ordered.