ISEE Middle Level Quantitative : Data Analysis

Study concepts, example questions & explanations for ISEE Middle Level Quantitative

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Example Questions

Example Question #1 : Find Median

Find the median of this set of numbers:

60, 74, 51, 43, 91,62, 65

Possible Answers:

Correct answer:

Explanation:

First, place the numbers in order from least to greatest:

Then, identify the middle number: 62.

 

Example Question #2 : Find Median

Give the median of the following nine scores: 

Possible Answers:

Correct answer:

Explanation:

Arrange the scores from least to greatest.

There are an odd number (nine) of scores, so the median of the scores is the one that falls in the center - namely, 72.

Example Question #3 : Find Median

What is the median of the following set of numbers:

 

Possible Answers:

No number is the median for this set of numbers

Correct answer:

Explanation:

The median is the number with an equal number of other items both above and below it.  There are 9 total numbers in the list, 4 of them are below 7, and 4 of them are above 7.

Example Question #1 : Median

What is the median of the values , , , , ?

Possible Answers:

Correct answer:

Explanation:

The median of a set of values is the value that is in the middle when you rearrange the values from least to greatest. In this set, the values can be rearranged as  and the median is .

Example Question #11 : Median

On a math test that the teacher gave her students, the scores were as follows:

What was the median score?

Possible Answers:

Correct answer:

Explanation:

The median is the middle number in a set when the set of numbers is ordered sequentially. 

When the intial set is reordered sequentially, you get the bottom set. (The top set is the original ordering of the numbers.)

In this sequential set of 7 numbers, the number 89 is in the fourth posiiton and exactly in the middle. Therefore, it is the mean. 

Example Question #1 : How To Find Median

What is the median of this set of numbers?

Possible Answers:

Correct answer:

Explanation:

To find the median of a set of numbers, you must first reorder them from smallest to largest. Below is the set reordered as such:

The median is the middle number of the set. Here, 57 is the middle number. Therefore, it is the median and the correct answer. 

Example Question #11 : How To Find Median

Given the following data sets of data, identify how the median would change if an additional data point of  was added to the new set? 

Data Set: 

New Data Set: 

Possible Answers:

Correct answer:

Explanation:

First, we need to find the median for the first data set: 

We must put the numbers in order from least to greatest: 

Since there is an even number of items in the data set, we will take the average of the middle two numbers to find the median. 

The median for this data set is:

 

Next, we must find the new median for the new data set: 

Again, we must put the numbers in order from least to greatest: 

Since there is an odd number of items, we can choose the middle number to be the median. 

In this case, the middle number is , which means the new median is:

Therefore, we know that the median will decrease by .

Example Question #12 : How To Find Median

Horatio's soccer team has scored the below number of goals in their last eight games, what is the median number of goals that have been scored? 

Possible Answers:

Correct answer:

Explanation:

First we must put the numbers  in order from least to greatest. 

After the numbers are in order, if it is an odd number of numbers we chose the middle number - that is the median. 

In this case, we have an even number of numbers, so we must take the average of the middle two numbers which is given below: 

So the median is !

Example Question #13 : How To Find Median

Horatio's soccer team has scored the below number of goals in their last  games: 

Horatio calculates the median to be  for this set of data. He then goes back and finds that the game where he thought they scored 9 goals; his team actually scored  goals - how will this change the median if he replaces the  with  in the data set? 

Possible Answers:

The median will increase by 

The median will remain unchanged

The median will increase by 

The median will increase by 

Correct answer:

The median will remain unchanged

Explanation:

When finding the median we must first reorganize the numbers from least to greatest, here is what the numbers are before and after they were organized. 

Given: 

After Organized from least to greatest: 

In order to find the Median for an even number of numbers (we have  numbers in this set) we take the average of the middle two numbers. 

Here we would add  which is , we then divide by two to find the mean which is

If we were to change the  to an , this does not impact the middle two numbers, they will remain  and  which means the Median will remain

The middle two numbers are still  and

The Median will remain unchanged.

Example Question #14 : How To Find Median

Find the median of the data set provided:

Screen shot 2016 04 05 at 8.55.18 am

Possible Answers:

Correct answer:

Explanation:

In order to answer this question correctly, we need to recall the definition of median:

Median: The median of a data set is the middle value, when the data set is ordered from least to greatest. 

In order to find the median, we need to first organize the data from least to greatest:

Next, we can solve for the median by finding the middlemost number in our data:

The median for this data set is 

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