The postoperative quality of life (QOL) scores of 200 prostate cancer patients have a mean of 60 and a standard detion of 10. How many patients are expected to have a QOL score between 40 and 80?
The values enclosed in a normal distribution curve are:Mean +- 1 SD 68% of data Mean +- 2 SD 95% of dataMean +- 3 SD 99% of dataIn the above question,Mean = 60SD = 10Hence, the range of values from 40 to 80 i.e. 60 +- 20 (Mean +- 2 SD) would include 95% of the readings.Therefore, the total number of readings in the given range = (95 x 200) / 100 = 190Hence, 190 patients are expected to have a QOL score between 40 and 80.
190
136
120
140
All India exam