Dom S. answered • 10/14/23
Experienced Medical graduate tutor especially in USMLE and ERAS
A. Mean is the average of all the data in a sample. So, in this example, it would be the sum of [51+94 +... 75] divided by the total number of values [11]. This comes out to [933]/[11] = 84.82 or 85 if that is an answer choice.
B. Median is the middle number. This data set should be arranged from lowest to most, and since there is an odd number of values, we use the middle number. The set should show 51, 56, 62, 75, 75, 83, 94, 98,105,114, 120. In bold, we can see that the middle number in this data set is 83 when arranged chronologically.
C. Mode is the most frequent number. This would be 75, as it comes up twice.
D. Variance is the difference from the mean of a data set. This is more difficult to calculate as you must complete the formula for each data point in the set, subtracting it from the mean calculated earlier and then squaring the value. (51-84.8)2+(56 - 84.8)2 + (62- 84.8)2 +(75- 84.8)2 +(75- 84.8)2 +(83- 84.8)2 +(94- 84.8)2 +(98- 84.8)2 +(105- 84.8)2 +(144- 84.8)2 +(120- 84.8)2= 7036.96 variance.
E. Standard deviation is how much a data set is dispersed to the mean. It is calculated with a formula where you subtract the data point by the mean, and that sum is squared. That value is then divided by the population size of the data points, and then the squared root is taken. This comes out to 24.07 in this data set.
F. is the Percentage Coefficient of variance, and it measures the ratio of the standard deviation to the mean.CV = (SD/x̄) * 100. Therefore, CV = (24.07/84.82) x 100 = 28.4%
