# GRE Subject Test: Math : Statistics

## Example Questions

### Example Question #31 : Mean

The average test score was an , the scores were as followed , and . Find

Explanation:

Use the mean equation:

Enter in the numbers

Simplify

Multiply each side by

Subtract  from both sides

### Example Question #31 : Other Topics

Find the variance of the scores 18, 4, 9, 6, 11, and 20.

Explanation:

First find the mean of the scores by adding them up and dividing by the number of scores.

Subtract the mean of 11.33 from each of the scores.

Now, square the results.

Now we need the average of these values to get the variance. First, add up these values.

Now divide by 6 which is the number of scores.

Explanation:

or

### Example Question #1 : Standard Deviation

What is the standard deviation of the numbers 3, 5, 8, 9, and 10?

Explanation:

The first step with standard deviation is to find the average or mean of the numbers. Add 3+5+8+9+10 together to get 35. Divide that by the number of scores, which is 5, to get a mean of 7.

Now, subtract the mean from each of the numbers

Next, square those values

Now find the mean of these squared differences by adding the values and then dividing by the amount of numbers, 5 in this case.

Finally, take the square root of this number to get the standard deviation.

### Example Question #1 : Range & Iqr

What is the range of the set of numbers: ?

Explanation:

Step 1: Arrange the numbers in the set from smallest to largest:

After we arrange, we get: .

Step 2: To find the range, subtract the largest number from the smallest number.

The range of the data set is .

### Example Question #2 : Range & Iqr

What is the range of the numbers:

Explanation:

Step 1: Re-write all numbers in order from smallest to largest

.

Step 2: Subtract the largest number and smallest number

The range is .

### Example Question #31 : Probability & Statistics

What is the range of the set: {}

Explanation:

Step 1: Arrange the numbers from smallest to largest:

We get:

Step 2: Find the range.. To find this, subtract the biggest number from the smallest number

The range is

### Example Question #4 : Range & Iqr

Find the range of the set of numbers:

Explanation:

Step 1: Arrange the numbers from smallest to largest. If the numbers are already written that way, then skip this step..

The numbers need to be arranged.. We will get:

Step 2: To find the range, subtract the smallest number from the biggest number...

So,

The range of this set of numbers is ...

### Example Question #1 : Range & Iqr

What is the range of the numbers:

Explanation:

Step 1: See if the numbers are in order..

The numbers are in order from smallest to largest..

Step 2: Subtract the largest number and the smaller number:

is the range.

### Example Question #1 : Range & Iqr

What is the range of:

Explanation:

Step 1: Rearrange the numbers from smallest to largest:

After rearranging, we have:

Step 2: Find the smallest number:

The smallest number is .

Step 3: Find the largest number:

The largest number is .

Step 4: Subtract the smallest number from the smallest number:

The range is .