# GRE Subject Test: Math : Probability & Statistics

## Example Questions

### Example Question #18 : Mean

What is the mean of ?

Explanation:

Step 1: Find the sum of all numbers:

Step 2: Count how many numbers are in the question..

We have  numbers.

Step 3: Divide sum by how many numbers

### Example Question #19 : Mean

What is the mean of

Explanation:

Step 1: Find the sum of the numbers

Step 2: Find how many numbers

There are  numbers..

Step 3: Divide the sum by how many numbers they are...This division gives us the mean..

### Example Question #20 : Mean

What is the mean of:

Explanation:

Step 1: Find the sum of the numbers

Step 2: Find how many numbers are there

I counted  numbers.

Step 3: Divide Sum by how many numbers

The mean is .

### Example Question #21 : Other Topics

What is the mean of:

Explanation:

Step 1: Find the sum of the numbers

Step 2: Count how numbers there are:

There are  numbers..

Step 3: Divide Sum by how many numbers

### Example Question #22 : Other Topics

What is the mean of:

Explanation:

Step 1: Find the sum of all the numbers:

Step 2: Count how many numbers there are:

There are 22 numbers.

Step 3: Divide the sum by how many numbers there are:

The mean is

### Example Question #21 : Probability & Statistics

What is the mean of:

Explanation:

Step 1: Take the sum of all numbers in the set...

Step 2: Count how many elements are in the set...

There are  numbers

Step 3: To find the mean, divide the sum by the number of elements..

The mean is

### Example Question #24 : Other Topics

In the set, , is the mean bigger than the median?

None

Cannot Tell

Yes

No

Yes

Explanation:

Step 1: Calculate the Mean..

Take the sum of all the numbers in the set...

Divide the sum by how many numbers there are...
=Mean
Step 2: Calculate the Median:
The median of this set is the number in the middle.

Count how many numbers are in the set...
There are ...

So, the median is the th number in the set.

The th number is .

The mean is bigger than the median, so the answer is true.

### Example Question #25 : Other Topics

Tommy got  on the first three tests. What must he score on the fourth test so that the average is 81?

Explanation:

Step 1: Find the total sum of the tests. To do this, we multiply the average by the number of tests:

Total=
Step 2: To find the missing term, we subtract each of the three test scores that are provided...

.

Tommy needs an  on his fourth test to get that average...

### Example Question #26 : Other Topics

What is the mean of

Explanation:

Step 1: Find the sum of the numbers in the set...

Step 2: Count how many numbers are in the set..

There are 10 numbers...

Step 3: Divide the total sum by how many numbers...

So,

### Example Question #22 : Mean

What is the mean of

Explanation:

Step 1: Find the sum of all the terms

Step 2: Count how many numbers are in the set

There are  numbers.

Step 3: Divide the sum (Step 1) by how many numbers in the set (Step 2)