*12. Using the data in Table 18.1 about a hypothetical population of 100,000 women tested for breast cancer, find the probability of each of the following events:

*a. A woman whose test shows a malignant lump actually has a benign lump.

*b. A woman who actually has a benign lump has a test that shows a malignant lump.

*c. A woman with unknown status has a test showing a malignant lump.