Answer:
I. Mean = 15
II. Median = 15
Explanation:
Given the following data;
Total number of students = 8
x = 18, 10, 20, 18, 12, 19,12, 11
F(x) = 18 + 10 + 20 + 18 + 12 + 19 + 12 + 11
F(x) = 120
To find the mean;
Mean = F(x)/n
Mean = 120/8
Mean = 15
To find the median;
Median refers to the middle number of a sorted data.
x = 10, 11, 12, 12, 18, 18, 19, 20
Middle numbers = 12 and 18
Median = (12 + 18)/2
Median = 30/2
Median = 15