Answer:
The correct option is D.
Step-by-step explanation:
The given data is
20, 21, 14, 21, 21, 12, 18, 23, 20, 23, 12
Arrange the data in ascending order.
12, 12, 14, 18, 20, 20, 21, 21, 21, 23, 23
Find the number that divides the data in two equal parts.
(12, 12, 14, 18, 20), 20,( 21, 21, 21, 23, 23)
Divide each parenthesis in two parts.
(12, 12), 14,( 18, 20), 20,( 21, 21), 21, (23, 23)
It means first quartile is 14, median is 20 and third quartile is 21.
Therefore option A and B are incorrect.
The interquartile range is
The interquartile range is 9. Therefore option C is incorrect.
If the data lies outside the interval , then it has outliers.
All the data lie in the interval [-2.5,37.5], therefore data has no outliers and option D is correct.