In: Statistics and Probability
The owner of a specialty coffee shop wants to study coffee purchasing habits of customers at her shop. She selects a random sample of 60 customers during a certain week. Data are available in the worksheet labeled “Problem 2”.
1. At the a = 0.1 level of significance, is there evidence that more than 50% of the customers say they “definitely will” recommend the specialty coffee shop to family and friends?
2. Construct a 90% confidence interval on the proportion of customers who say they “definitely will” recommend the specialty coffee shop to family and friends.
| Note: Y is an indicator variable, i.e., if Y=1, then customer said they "definitely would" recommend specialty shop to family and friends, and Y=0 otherwise. |
Problem 2 Data Set
| Customer | Y |
| 1 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 0 |
| 7 | 0 |
| 8 | 1 |
| 9 | 1 |
| 10 | 1 |
| 11 | 0 |
| 12 | 1 |
| 13 | 0 |
| 14 | 1 |
| 15 | 0 |
| 16 | 1 |
| 17 | 1 |
| 18 | 1 |
| 19 | 0 |
| 20 | 1 |
| 21 | 1 |
| 22 | 0 |
| 23 | 0 |
| 24 | 0 |
| 25 | 0 |
| 26 | 1 |
| 27 | 0 |
| 28 | 0 |
| 29 | 1 |
| 30 | 0 |
| 31 | 1 |
| 32 | 1 |
| 33 | 0 |
| 34 | 0 |
| 35 | 0 |
| 36 | 1 |
| 37 | 0 |
| 38 | 1 |
| 39 | 1 |
| 40 | 1 |
| 41 | 1 |
| 42 | 0 |
| 43 | 1 |
| 44 | 0 |
| 45 | 1 |
| 46 | 0 |
| 47 | 1 |
| 48 | 0 |
| 49 | 0 |
| 50 | 0 |
| 51 | 1 |
| 52 | 1 |
| 53 | 1 |
| 54 | 0 |
| 55 | 1 |
| 56 | 0 |
| 57 | 0 |
| 58 | 0 |
| 59 | 1 |
| 60 | 1 |
Solution


(5) Conclusion
It is concluded that the null hypothesis Ho is not rejected. Therefore, there is not enough evidence to claim that the more than 50% of the customers say they “definitely will” recommend the specialty coffee shop to family and friends, at the α=0.10 significance level.