Question

3. What is the value of first quartile for obser
vations?
15, 18, 10, 20, 23, 28, 12, 16
1. 17
2.16
3. 12.75
4. 12
​

Answer 1

Answer:

Step-by-step

explanation:

The 1st quartile is the median of the numbers below the

median of the whole data set.

There is no way the answer could be 15.75. So you should point

this out to your teacher. Very little educational material is

free of typos. Where there are humans, there is usually some

human error.

Arrange the data in ascending order:

10,12,15,16,18,20,23,28

Find the median of the whole data set. Since there are an even

number of numbers in the data set, the median is the average of

its two middle numbers (16+18)÷2 = 34÷2 or 17.

Next we find the median of the numbers below the median of the

whole data set, 17. These numbers are 10,12,15,16. Since there

are also an even number of numbers in this data set, the median

is the average of its two middle numbers (12+15)÷2 = 27÷2 or 13.5.