The monthly rainfall for the first eight months of 2008. . .

This topic has expert replies
Moderator
Posts: 2058
Joined: Sun Oct 29, 2017 4:24 am
Thanked: 1 times
Followed by:5 members
The monthly rainfall for the first eight months of 2008 in inches was 2, 4, 4, 5, 7, 9, 10, 11. Which one of the following equals the mean monthly rainfall for the 8 months and the median of the rainfall for the 8 months, respectively?

(A) 6.5, 6

(B) 6, 7.5

(C) 7, 8

(D) 8, 9

(E) 8.5, 9.5

The OA is A.

This kind of questions is difficult for me. Experts, can you clarify this PS question for me? Thanks.

User avatar
GMAT Instructor
Posts: 555
Joined: Wed Oct 04, 2017 4:18 pm
Thanked: 180 times
Followed by:12 members

by EconomistGMATTutor » Sun Dec 17, 2017 9:24 am
The monthly rainfall for the first eight months of 2008 in inches was 2, 4, 4, 5, 7, 9, 10, 11. Which one of the following equals the mean monthly rainfall for the 8 months and the median of the rainfall for the 8 months, respectively?

(A) 6.5, 6

(B) 6, 7.5

(C) 7, 8

(D) 8, 9

(E) 8.5, 9.5

The OA is A.

This kind of questions is difficult for me. Experts, can you clarify this PS question for me? Thanks.
Hi M7MBA,
Let's take a look at your question.

The monthly rainfall for the first eight months of 2008 in inches was 2, 4, 4, 5, 7, 9, 10, 11.
$$Mean=\frac{\text{Sum of Quantities}}{\text{Number of Quantities}}$$
$$Mean=\frac{2+4+4+5+7+9+10+11}{8}$$
$$Mean=\frac{52}{8}=6.5$$

The data is already in ascending order, so we can find the median.
2, 4, 4, 5, 7, 9, 10, 11
There are a total of 8 values, therefore, Median is the average of the middle two values 5 and 7.
$$Median=\frac{5+7}{2}=\frac{12}{2}=6$$

Therefore, Option A is correct.

Hope it helps.
I am available if you'd like any followup.
GMAT Prep From The Economist
We offer 70+ point score improvement money back guarantee.
Our average student improves 98 points.

Image

GMAT/MBA Expert

User avatar
GMAT Instructor
Posts: 7209
Joined: Sat Apr 25, 2015 10:56 am
Location: Los Angeles, CA
Thanked: 43 times
Followed by:29 members

by Scott@TargetTestPrep » Mon Sep 16, 2019 10:22 am
M7MBA wrote:The monthly rainfall for the first eight months of 2008 in inches was 2, 4, 4, 5, 7, 9, 10, 11. Which one of the following equals the mean monthly rainfall for the 8 months and the median of the rainfall for the 8 months, respectively?

(A) 6.5, 6

(B) 6, 7.5

(C) 7, 8

(D) 8, 9

(E) 8.5, 9.5

The OA is A.

This kind of questions is difficult for me. Experts, can you clarify this PS question for me? Thanks.
Since the median is easier to calculate than the mean, let's calculate the median first. Recall that we list the data values in ascending order, and the median is the middle value. In this case, since there is no single value in the middle, the median is the average of the two middle values:

Median = (5 + 7)/2 = 6

Since only choice A has 6 as the median, A is the correct answer.

Answer: A

Scott Woodbury-Stewart
Founder and CEO
[email protected]

Image

See why Target Test Prep is rated 5 out of 5 stars on BEAT the GMAT. Read our reviews

ImageImage