Question

DPH 623, Biostatistics I class has 10 students. The instructor surveyed the birth month during the class. The following is the raw data which has also the instructor’s birth month. So, the number of total sample is 11. 7, 12, 11, 9, 11, 6, 3, 8, 12, 12, 8 Based on the shape of the data, what do you think the best central tendency methods is? Median Mean Mode Cannot be determined

Answer 1

Soln,

The given data are

3,6,7,8,8,9,11,11,11,12,12,12

and no of data are n= 10 studenst , the frequecy histogram is below which shows the distribution of data .

Mean (x?): 9.17
Median: 10
Modes: 11 12
Lowest value: 3
Highest value: 12
Range: 9
Interquartile range: 4.5
First quartile: 7.25
Third quartile: 11.75
Variance (s²): 8.15
Standard deviation (s): 2.855

By looking at the data diagram we can say that data is not symmetric and not normally distributed hence we cannot use mean as the measure of central tendency here ,Since the data is skewed and bimodal also than we should use MEDIAN as the measure of central tendency.