Answers
1. Minimum = 4
2. First quartile = 6.5
3. Median = 13.5
4. Third quartile = 19
5. Maximum = 20
Step-by-step explanation
To calculate the measure of central tendency, you first arrange the set of the data in ascending order.
The set of data given will be;
4, 4, 9, 9, 18, 18, 20, 20.
Part 1:
The minimum value of the data is 4.
Part 2:
The first quatile is the median of the lower half which is comprised by:
4, 4, 9, 9
1st quartile = (4+9)÷2
= 13÷2
= 6.5
Part 3:
Median of the data is;
Median = (9+18)÷2
=27÷2
= 13.5
Part 4:
3rd quartile is the median of the upper half which comprises of;
18, 18, 20, 20.
3rd quartile = (18+20)÷2
= 48÷2
= 19
Part 5
The maximum of the set of data is 20.