A study (B. Kristensen et al., J. Intern. Med., 232: 237–245, 1992) considered the effect of prednisolone on severe hypercalcaemia in women with metastatic breast cancer. Of 30 patients, 15 were randomly selected to receive prednisolone, and the other 15 formed a control group. Normalization in their level of serum-ionized calciumwas achieved by seven of the 15 prednisolone-treated patients and by 0 of the 15 patients in the control group. Use Fisher’s exact test to find a P-value for testing whether results were significantly better for treatment than control. Interpret.