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.
The monthly rainfall for the first eight months of 2008. . .
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- EconomistGMATTutor
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Hi M7MBA,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.
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.
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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: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.
Median = (5 + 7)/2 = 6
Since only choice A has 6 as the median, A is the correct answer.
Answer: A
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