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 calcium was achieved by 7 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.