ISEE Middle Level Quantitative : ISEE Middle Level (grades 7-8) Quantitative Reasoning

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

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Example Questions

Example Question #81 : Data Analysis

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 #82 : Data Analysis

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 #12 : 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 remain unchanged

The median will increase by 

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 : 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 

Example Question #21 : Median

Find the median of the data set provided:

Screen shot 2016 04 05 at 9.44.17 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 

Example Question #15 : Find Median

Find the median of the data set provided:

Screen shot 2016 04 05 at 10.03.05 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 

Example Question #22 : Median

Find the median of the data set provided:

Screen shot 2016 04 05 at 10.19.45 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 

Example Question #1 : How To Find The Answer From A Table

Choose the best answer from the four choices given.

Katie wants to buy as many umbrellas as she can to give to her friends as Christmas gifts. She finds a deal online where she can get umbrellas for $7 each or four umbrellas for $25 (including tax). If shipping is $3 for every $20 of merchandise (or portion thereof), how many umbrellas can she buy if she has $140?

Possible Answers:

Correct answer:

Explanation:

The quickest way to solve this problem is by making a chart showing the units purchased and the total cost. Start with the 4-packs of umbrellas:

4-packs      cost        shipping cost              total cost

1                $25               $6                          $31        

2                $50               $9                          $59

3                $75               $12                        $87

4                $100             $15                        $115

5                $125             $21                        $146 (too high)

 

Having determined that Katie can buy four of the 4-packs of umbrellas, now we see how many of the $7 individual umbrellas she can add to her order.

 

four 4-packs        indiv.        indiv. $     subtotal     shipping $      total $

$100                      1               $7           $107         $18          $125

$100                      2               $14         $114         $18           $132

$100                      3               $21         $121         $21          $142 (too high)

 

Therefore, Katie can buy (4) 4-packs and (2) individual umbrellas (18 total umbrellas) for $132.

ALTERNATIVELY, you can begin by determining the highest subtotal she can afford and work backwards from there. $120 is 6 x $20, so the shipping charge would be $6 x 3 = $18, for a total cost of $138. One more dollar on the subtotal would bring it into the next $20 segment, bringing the shipping charge up to $21 (and $142 is greater than $140). Thus, from here you could figure out the maximum number of $25 4-packs and $7 individual umbrellas Katie could buy with $120.

Since $6 is not enough to buy any umbrellas, the total would be

Example Question #91 : Data Analysis

The table below gives the population of Buchanan City in each census year from 1930  to 1980.

Which is the greater quantity?

(a) The decline in the population of Buchanan City between 1940 and 1950

(b) The growth in the population of Buchanan City between 1950 and 1960

Possible Answers:

It is impossible to tell from the information given

(a) and (b) are equal

(a) is greater

(b) is greater

Correct answer:

(b) is greater

Explanation:

The population of Buchanan City in 1960 is greater than it was in 1940, so its decline between 1940 and 1950 must be less than its growth between 1950 and 1960.

Example Question #3 : How To Find The Answer From A Table

The table below gives the population of Buchanan City in each census year from 1930  to 1980.

Which is the greater quantity?

(a) The growth in the population of Buchanan City between 1930 and 1940

(b) The growth in the population of Buchanan City between 1950 and 1960

Possible Answers:

(b) is greater

(a) is greater

It is impossible to tell from the information given

(a) and (b) are equal

Correct answer:

(b) is greater

Explanation:

(a) Between 1930 and 1940, the population grew by 

(b) Between 1950 and 1960, the population grew by .

This makes (b) greater

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