Question

Which statement about class ll is true
A?
B?
C?
D?

Answer 1

The mean of class II is larger and the median is the same

Explanation:

Class I

14,15,15,16,16,16,17,17,18

The mean is

(14+15+15+16+16+16+17+17+18)/9

144/9 = 16

The median is the middle number

14,15,15,16, 16, 16,17,17,18

median = 16

Class II

13,14,15,16,16,17,18,18,19

The mean is

(13+14+15+16+16+17+18+18+19)/9

146/9 = 16.2repeating

The median is the middle number

13,14,15,16 ,16, 17,18,18,19

median = 16

Answer 2

D

Explanation:

Let's first find the mean and median of each class.

Class 1:

The mean is simply all the numbers added up and then divided by the number of elements. There are 9 students in Class 1. Thus, we add all the ages up and then divide by 9. Thus:

`\text{Class 1 Mean }= (14+15+15+16+16+16+17+17+18)/(9) \\=144/9=16`

The median is simply the middle number when the data sets are placed in order. The median of Class 1 is 16, the number in the middle.

Class 2:

Again, Class 2 has 9 students. Add up all the ages and then divide:

`\text{Class 2 Mean }= (13+14+15+16+16+17+18+18+19)/(9)\\ =146/9\approx16.2222`

The median is the middle number of the data set. The median of Class 2 is 16.

Therefore, the mean of Class 2 is larger than the mean of Class 1. The medians of the two classes are equivalent.

Of the answer choices given, only D is correct.