2. A firm is considering the delivery times of two raw materialsuppliers, A and B. The firm is basically satisfied with supplierA; however, if the firm finds the mean delivery time of supplier Bis less than the mean delivery time of supplier A, the firm willbegin purchasing raw materials from supplier B (meaning, switchfrom supplier A to supplier B). Independent samples (assume equalpopulation variances) show the following sample data for thedelivery times of the two suppliers:
| SUPPLIER |
SUMMARY DATA | A | B |
Sample Mean | 15 days | 12 days |
Sample Standard Deviation | 5 days | 4 days |
Sample Size | 61 | 41 |
a. State the null and alternative hypotheses for thissituation.
b. Describe what a Type I Error would be in this situation (pleasebe as specific as possible).
c. If ? = 0.01, what is the critical value of the associated teststatistic?
d. What is the calculated value of the associated teststatistic?
e. State your decision about the null hypothesis by comparing thecritical and calculated values of the test statistic (Parts c andd).
f. What action do you recommend in terms of supplier selection?
