Explanation Correct answer: Sample 3 Remember that standard deviation is a measure of how spread out the values are. We can get a very rough estimate of the standard deviation for each data set using the formula for the range rule of thumb: standard deviation range 4 maximum value minimum value 4 The data set with the smallest result will have the smallest standard deviation and the least spread. The data set with the largest result will have the largest standard deviation and the most spread. Sample 1: Estimation of standard deviation 39.2 18.7 4 20.5 4 5.125 Sample 2: Estimation of standard deviation 45.9 23.4 4 22.5 4 5.625 Sample 3: Estimation of standard deviation 31.0 19.2 4 11.8 4 2.95 Sample 4: Estimation of standard deviation 52.6 20.6 4 32.0 4 8.0 We see that Sample 3 consisting of 30.8 , 19.2 , 29.9 , 25.6 , 28.8 , 31.0 , 27.3 has the smallest estimated standard deviation. Therefore, Sample 3 has the least amount of variation or spread.Question Body mass index (BMI) is a medical screening tool