Median - GRE Quantitative Reasoning
Card 0 of 8
The medians of the following two sets of numbers are equal, and
the sets are arranged in ascending order
{1, 4, x, 8} and {2, 5, y, 9}. What is y – x?
The medians of the following two sets of numbers are equal, and
the sets are arranged in ascending order
{1, 4, x, 8} and {2, 5, y, 9}. What is y – x?
Answer: –1
Explanation: Recall that the median of an even-numbered set of numbers is the arithmetic mean of the pair of middle terms. Thus (4 + x)/2 = median of the first set and (5 + y)/2 = median of the second set. Since both medians are equal, we can set the equations equal to eachother. (4 + x)/2 = (5 + y)/2. Multiply both sides by 2 and we get 4 + x = 5 + y. We also know that 4 < x < 8 and 5 < y < 9, since the sets are arranged in ascending order. This narrows our options for x and y down significantly. Plugging in various values will eventually get you to x = 7 and y = 6, since 7 + 4 = 11 and 5 + 6 = 11, and thus the median in both cases would be 5.5. Thus, y – x = –1.
Answer: –1
Explanation: Recall that the median of an even-numbered set of numbers is the arithmetic mean of the pair of middle terms. Thus (4 + x)/2 = median of the first set and (5 + y)/2 = median of the second set. Since both medians are equal, we can set the equations equal to eachother. (4 + x)/2 = (5 + y)/2. Multiply both sides by 2 and we get 4 + x = 5 + y. We also know that 4 < x < 8 and 5 < y < 9, since the sets are arranged in ascending order. This narrows our options for x and y down significantly. Plugging in various values will eventually get you to x = 7 and y = 6, since 7 + 4 = 11 and 5 + 6 = 11, and thus the median in both cases would be 5.5. Thus, y – x = –1.
Compare your answer with the correct one above
There are 3,500 people in group A and 5,000 people in group B:
Car Type % in Group A Who Own % in Group B Who Own Motorbike 4 9 Sedan 35 25 Minivan 22 15 Van 9 12 Coupe 3 6
What is the median of the number of people in group B who own either a minivan, van, or coupe?
There are 3,500 people in group A and 5,000 people in group B:
| Car Type | % in Group A Who Own | % in Group B Who Own |
|---|---|---|
| Motorbike | 4 | 9 |
| Sedan | 35 | 25 |
| Minivan | 22 | 15 |
| Van | 9 | 12 |
| Coupe | 3 | 6 |
What is the median of the number of people in group B who own either a minivan, van, or coupe?
Treat the percentages as a list, as we are including every demographic from the 3 vehicle types mentioned. If we do each 0.06(5000), 0.12(5000), and 0.15(5000) we note from observation that the median, or middle value, would have to be the 12% row since the sample size does not change. The question asks for EITHER of the 3 categories, so we can ignore the other two.
0.12(5000) = 600(van) is the median of the 3 categories.
Treat the percentages as a list, as we are including every demographic from the 3 vehicle types mentioned. If we do each 0.06(5000), 0.12(5000), and 0.15(5000) we note from observation that the median, or middle value, would have to be the 12% row since the sample size does not change. The question asks for EITHER of the 3 categories, so we can ignore the other two.
0.12(5000) = 600(van) is the median of the 3 categories.
Compare your answer with the correct one above
Find the median:
Find the median:
To find the median, arrange the numbers from smallest to largest:
4,4,4,4,6,7,9,9,12,12,12,12,12,12,18,76,90
There are 17 numbers in total. Since 17 is an odd number, the median will be the middle number of the set. In this case, it is the 9th number, which is 12.
To find the median, arrange the numbers from smallest to largest:
4,4,4,4,6,7,9,9,12,12,12,12,12,12,18,76,90
There are 17 numbers in total. Since 17 is an odd number, the median will be the middle number of the set. In this case, it is the 9th number, which is 12.
Compare your answer with the correct one above
What is the median in the following set of numbers?
16, 19, 16, 7, 2, 20, 9, 5
What is the median in the following set of numbers?
16, 19, 16, 7, 2, 20, 9, 5
16, 19, 16, 7, 2, 20, 9, 5
Order the numbers from smallest to largest.
2,5,7,9,16,16,19,20
The median is the number in the middle.
In this case, there is a 9 and 16 in the middle.
When that happens, take the average of the two numbers.
16, 19, 16, 7, 2, 20, 9, 5
Order the numbers from smallest to largest.
2,5,7,9,16,16,19,20
The median is the number in the middle.
In this case, there is a 9 and 16 in the middle.
When that happens, take the average of the two numbers.
Compare your answer with the correct one above
In the set above, which is larger: the median, the mean, or the mode?
In the set above, which is larger: the median, the mean, or the mode?
Begin by ordering the set from smallest to largest:
Already, we see that the mode is 8. Find the median by taking the average of the two middle numbers:
Find the mean by adding all numbers and dividing by the total number of terms:
Of the three, the mean of the set is the largest.
Begin by ordering the set from smallest to largest:
Already, we see that the mode is 8. Find the median by taking the average of the two middle numbers:
Find the mean by adding all numbers and dividing by the total number of terms:
Of the three, the mean of the set is the largest.
Compare your answer with the correct one above
The grades on a test taken by 
students are 
respectively. What was the median score for this test?
The grades on a test taken by
To solve this problem, we must be aware of the definition of a median for a set of numbers. The median is defined as the number that is in middle of a set of numbers sorted from smallest to largest. Therefore we must first sort the numbers from largest to smallest.
34,43,45,50,56,65,70,76,76,82,87,88,92,95,100
43,45,50,56,65,70,76,76,81,87,88,82,95
45,50,56,65,70,76,76,81,87,88,82
50,56,65,70,76,76,81,87,88
56,65,70,76,76,81,87
65,70,76,76,81
70,76,76
76
Then by slowly eliminating the smallest and the largest numbers we find that the median score for this test is 76.
To solve this problem, we must be aware of the definition of a median for a set of numbers. The median is defined as the number that is in middle of a set of numbers sorted from smallest to largest. Therefore we must first sort the numbers from largest to smallest.
34,43,45,50,56,65,70,76,76,82,87,88,92,95,100
43,45,50,56,65,70,76,76,81,87,88,82,95
45,50,56,65,70,76,76,81,87,88,82
50,56,65,70,76,76,81,87,88
56,65,70,76,76,81,87
65,70,76,76,81
70,76,76
76
Then by slowly eliminating the smallest and the largest numbers we find that the median score for this test is 76.
Compare your answer with the correct one above
The arithmetic mean of 
is 
The median of 
The arithmetic mean of
is an unknown value, but it can be found given what we know about the mean of the set 
:
Now, 
is out of order; arrange in numerically:
Since there are even number of values, the median is the mean of the two middle most values:
Now,
Since there are even number of values, the median is the mean of the two middle most values:
Compare your answer with the correct one above
Quantity A: The mean of 
Quantity B: The median of 
Quantity A: The mean of
Quantity B: The median of
Begin by reordering the set in numerical order:
Then becomes
Since there is an odd number of values, the median is the middle value.
Quantity B: 
Now, to find the arithmetic mean, take the sum of values divided by the total number of values.
Quantity A: 
Begin by reordering the set in numerical order:
Then becomes
Since there is an odd number of values, the median is the middle value.
Quantity B:
Now, to find the arithmetic mean, take the sum of values divided by the total number of values.
Quantity A:
Compare your answer with the correct one above