Algebra 1 : Statistics and Probability

Study concepts, example questions & explanations for Algebra 1

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Example Questions

Example Question #12 : Mean

Reginald has scores of {87, 79, 95, 91} on the first four exams in his Spanish class. What is the minimum score he must get on the fifth exam to get an A (90 or higher) for his final grade?

Possible Answers:

98

95

82

71

90

Correct answer:

98

Explanation:

To find the fifth score, we need to set the average of all of the scores equal to 90.

Multiply both sides of the equation by 5.

Subtract 352 from both sides of equation.

Example Question #11 : Basic Statistics

The mean of the following set is 8. What is ?

 

Possible Answers:

Cannot be determined

8

9

2

1

Correct answer:

1

Explanation:

Let .

We know the mean is 8, and there are five values in the set, including the unknown .

Simplify.

Plug back into equation at top.

Example Question #1461 : Algebra 1

Given the set of numbers, find the mean.  

Possible Answers:

Correct answer:

Explanation:

The mean is the average of the set of numbers.   Add all the numbers in the set and divide by the total numbers in the set.

There are 6 numbers in the set.

Example Question #41 : Statistics And Probability

What is the mean?

Possible Answers:

Correct answer:

Explanation:

To find mean, we add the sum of the numbers and divide it by the total numbers in the set.

The sum is 

 or .

There are five numbers.

So  divided by  is 

Example Question #41 : Statistics And Probability

Find the mean.

Possible Answers:

Correct answer:

Explanation:

To find mean, we add the total numbers up which is just .

There are five numbers.

So  divided by  is 

Example Question #11 : Mean

If the average of  numbers is  and the average of  numbers is , what was the number added to increase the average?

Possible Answers:

Correct answer:

Explanation:

If the average of  numbers is , then the sum is .

We also know the average of  numbers is . We can set-up an equation. 

.

The expression in the numerator represents the sum. By cross-multiplying, we get 

 or  as the final answer. 

Example Question #11 : Basic Statistics

If the average of  numbers is  and the average of  numbers is , what is the average of all the numbers?

Possible Answers:

Correct answer:

Explanation:

To find the average of all the numbers, we need to find the sums from each average. Since the average of  numbers is , that means the sum is .

The average of  numbers is  means the sum is .

Then, the total sum is  which is the sum of all the numbers.

So to find average, we do  divided by  to get 

Example Question #41 : How To Find Mean

If the average of  numbers is  and one of the number was  what was the other number?

Possible Answers:

Correct answer:

Explanation:

We know the average of the  numbers is . We can set-up an equation as 

.

When we cross-multiply, we get .

We know one of the value which is . Let's say that's .

So .

Then  is 

Example Question #41 : Statistics And Probability

If the average of  numbers is  and one of the number is  what is the other number?

Possible Answers:

Correct answer:

Explanation:

We know the average of the  numbers is . We can set-up an equation as 

.

When we cross-multiply, we get .

We know one of the value which is . Let's say that's .

So .

Then  is 

Example Question #43 : How To Find Mean

If the average of  numbers is  and the sum of two numbers is , what is the third number?

Possible Answers:

Correct answer:

Explanation:

If the average of  numbers is , the sum of the three numbers is . We can set-up an equation of 

.

We know the sum of two numbers is .

So then we can write .

Then  and is the final answer. 

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