GED Math : Median

Study concepts, example questions & explanations for GED Math

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Example Questions

Example Question #11 : Median

A class took a Math exam. Here are the test scores of 9 students.

\(\displaystyle 84, 76, 81, 88, 91, 85, 76, 90, 80\)

Find the median.

Possible Answers:

\(\displaystyle 85\)

\(\displaystyle 84\)

\(\displaystyle 90\)

\(\displaystyle 80\)

\(\displaystyle 81\)

Correct answer:

\(\displaystyle 84\)

Explanation:

To find the median of a data set, we will first arrange the numbers in ascending order. Then, we will find the number in the middle of the set. So, given the set

\(\displaystyle 84, 76, 81, 88, 91, 85, 76, 90, 80\)

we will arrange the numbers in ascending order (from smallest to largest). We get

\(\displaystyle 76, 76, 80, 81, 84, 85, 88, 90, 91\)

Now, we will find the number in the middle of the set.

\(\displaystyle 76, 76, 80, 81, {\color{Red} 84}, 85, 88, 90, 91\)

Therefore, the median of the data set is 84. 

Example Question #103 : Statistics

Determine the median of the numbers:  \(\displaystyle [-5,13,-21,-12]\)

Possible Answers:

\(\displaystyle \frac{25}{4}\)

\(\displaystyle -\frac{25}2\)

\(\displaystyle -\frac{25}{4}\)

\(\displaystyle - \frac{17}{2}\)

\(\displaystyle -\frac{1}{4}\)

Correct answer:

\(\displaystyle - \frac{17}{2}\)

Explanation:

Reorder the numbers from least to greatest.

\(\displaystyle [-5,13,-21,-12] \rightarrow [-21,-12,-5,13]\)

The median is the average of the central numbers of an ordered set of numbers.

\(\displaystyle \frac{-12+(-5)}{2} = \frac{-17}{2} =- \frac{17}{2}\)

The answer is:  \(\displaystyle - \frac{17}{2}\)

Example Question #101 : Calculations

Determine the median:  \(\displaystyle [5,-6,-7,14]\)

Possible Answers:

\(\displaystyle -\frac{1}{2}\)

\(\displaystyle -\frac{1}{4}\)

\(\displaystyle -\frac{13}{4}\)

\(\displaystyle \frac{3}{2}\)

\(\displaystyle -\frac{13}{2}\)

Correct answer:

\(\displaystyle -\frac{1}{2}\)

Explanation:

Rewrite the data set from least to greatest.

\(\displaystyle [5,-6,-7,14] \rightarrow [-7,-6,5,14]\)

Average the central two numbers.

\(\displaystyle \frac{-6+5}{2} = -\frac{1}{2}\)

The answer is:   \(\displaystyle -\frac{1}{2}\)

Example Question #103 : Calculations

Find the median:  \(\displaystyle [-9,11,-3,1,0]\)

Possible Answers:

\(\displaystyle 20\)

\(\displaystyle 1\)

\(\displaystyle 11\)

\(\displaystyle -3\)

\(\displaystyle 0\)

Correct answer:

\(\displaystyle 0\)

Explanation:

Reorder the numbers in the data set from least to greatest.

\(\displaystyle [-9,11,-3,1,0]\rightarrow [-9,-3,0,1,11]\)

The median is the central number for an odd set of numbers.

The answer is:  \(\displaystyle 0\)

Example Question #12 : Median

Identify the median:  \(\displaystyle [2,8,3,0,-5,-4]\)

Possible Answers:

\(\displaystyle \textup{There is no median.}\)

\(\displaystyle \frac{3}{2}\)

\(\displaystyle 1\)

\(\displaystyle \frac{2}{3}\)

\(\displaystyle \frac{1}{3}\)

Correct answer:

\(\displaystyle 1\)

Explanation:

Reorder the numbers from least to greatest.

\(\displaystyle [2,8,3,0,-5,-4]\rightarrow [ -5,-4,0,2,3,8]\)

For an even number of values in a set of data, the median is the average of the central two numbers.

\(\displaystyle \frac{0+2}{2} = 1\)

The answer is:  \(\displaystyle 1\)

Example Question #111 : Calculations

Give the median of the following test scores:

12, 34, 22, 28, 22, 28, 19, 20, 19, 22, 29, 35, 23 

Possible Answers:

\(\displaystyle 25\)

\(\displaystyle 22\)

\(\displaystyle 23\)

\(\displaystyle 28\)

Correct answer:

\(\displaystyle 22\)

Explanation:

There are thirteen test scores, an odd number, so the median of the test scores is the score which, after the scores are ordered, appears in the middle. Order the scores from greatest to least:

12, 19, 19, 20, 22, 22, 22, 23, 28, 28, 29, 34, 35 

As there are \(\displaystyle N= 13\) scores, we are seeking out the score that ranks at number

\(\displaystyle \frac{N + 1}{2} = \frac{13+1}{2} = 7\) 

That is, the median is the seventh-highest score. This score can be seen to be 22.

Example Question #112 : Statistics

Give the median of the following test scores:

12, 34, 22, 28, 22, 28, 19, 20, 19, 22, 29, 50, 35, 23

Possible Answers:

\(\displaystyle 25.5\)

\(\displaystyle 22.5\)

\(\displaystyle 22\)

\(\displaystyle 23\)

Correct answer:

\(\displaystyle 22.5\)

Explanation:

There are fourteen test scores, an even number, so the median of the test scores is the arithmetic mean of the two scores which, after the scores are ordered, appear in the middle. Order the scores from greatest to least:

12, 19, 19, 20, 22, 22, 22, 23, 28, 28, 29, 34, 35, 50

As there are \(\displaystyle N= 14\) scores, we are seeking out the score that ranks at number

\(\displaystyle \frac{N }{2} = \frac{14}{2} = 7\)

from the top, and number 7 from the bottom.  

That is, the median is the arithmetic mean of the seventh-highest and seventh-lowest scores. These scores can be seen to be 22 and 23, so the median of the scores is 

\(\displaystyle M = \frac{22+ 23}{2} = \frac{45}{2} = 22.5\)

Example Question #112 : Calculations

Identify the median:  \(\displaystyle [-2,-2,-9,-9,10,10]\)

Possible Answers:

\(\displaystyle -2\)

\(\displaystyle -9\)

\(\displaystyle 0\)

\(\displaystyle -1\)

\(\displaystyle -\frac{1}{3}\)

Correct answer:

\(\displaystyle -2\)

Explanation:

Reorder the numbers from least to greatest.

\(\displaystyle [-2,-2,-9,-9,10,10]\rightarrow [ -9,-9,-2,-2,10,10]\)

For an even amount of numbers given, the median is the average of the central two numbers.

\(\displaystyle \frac{-2+(-2)}{2} = \frac{-4}{2}\)

The answer is:  \(\displaystyle -2\)

Example Question #112 : Statistics

Use the following data set of student test scores to answer the question:

\(\displaystyle 88, 81, 90, 94, 85, 95, 90\)

 

Find the median.

Possible Answers:

\(\displaystyle 81\)

\(\displaystyle 95\)

\(\displaystyle 84\)

\(\displaystyle 90\)

\(\displaystyle 89\)

Correct answer:

\(\displaystyle 90\)

Explanation:

To find the median of a data set, we will first arrange the numbers in ascending order. Then, we will find the number in the middle of the set.

So, given the data set

\(\displaystyle 88, 81, 90, 94, 85, 95, 90\)

we will arrange the numbers in ascending order (from smallest to largest). We get

\(\displaystyle 81, 85, 88, 90, 90, 94, 95\)

Now, we will find the number in the center. We get

\(\displaystyle 81, 85, 88,{\color{Red} 90}, 90, 94, 95\)

We can see that it is 90.

Therefore, the median of the data set is 90.

Example Question #116 : Calculations

Use the following data set to answer the question:

\(\displaystyle 6, 5, 6, 8, 6, 3, 2, 5, 6, 1, 3\)

 

Find the median.

Possible Answers:

\(\displaystyle 6\)

\(\displaystyle 8\)

\(\displaystyle 5\)

\(\displaystyle 3\)

\(\displaystyle 11\)

Correct answer:

\(\displaystyle 5\)

Explanation:

To find the median of a data set, we will first arrange the numbers in ascending order. Then, we will find the number in the middle of the set.

So, given the data set

\(\displaystyle 6, 5, 6, 8, 6, 3, 2, 5, 6, 1, 3\)

we will first arrange the numbers in ascending order (from smallest to largest). So, we get

\(\displaystyle 1, 2, 3, 3, 5, 5, 6, 6, 6, 6, 8\)

Now, we will find the number in the middle.

\(\displaystyle 1, 2, 3, 3, 5, {\color{Red} 5}, 6, 6, 6, 6, 8\)

We can see that it is 5.

Therefore, the median of the data set is 5.

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