Mean - Basic Arithmetic

Card 0 of 20

Question

Find the mean of the following numbers:

150, 88, 141, 110, 79

Answer

The mean is the average. The mean can be found by taking the sum of all the numbers (150 + 88 + 141 + 110 + 79 = 568) and then dividing the sum by how many numbers there are (5).

Our answer is 113 3/5, which can be written as a decimal.

Therefore 113 3/5 is equivalent to 113.6, which is our answer.

Compare your answer with the correct one above

Question

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?

Answer

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.

Compare your answer with the correct one above

Question

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

Answer

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.

Compare your answer with the correct one above

Question

What is the mean of 44, 22, 134, and 200?

Answer

To find the mean, you must add all of the numbers together and divide by the amount of numbers. In this case there are four numbers so, we must deivide the total sum by 4.

Compare your answer with the correct one above

Question

Calculate the mean of the following numbers: 11, 13, 16, 13, 14, 19, 13, 13

Answer

First, calculate the sum of all of the numbers.

Next, divide by the total number.

Compare your answer with the correct one above

Question

The class average in a class of 15 is 86%. If one additional student earns a 100% in the class, what is the new class average.

Answer

We can treat this as if the entire class had exactly 86% as their average, so the new average is:

Compare your answer with the correct one above

Question

What is the mean of the following numbers?

88,99,31,47,68,27

Answer

To find the mean you add all of the numbers together and divide it by the amount of numbers. In this case there are six numbers so

The answer is .

Compare your answer with the correct one above

Question

Sally's algebra grade depends on three unit tests and a final exam. The grade for the final exam is weighted to equal the grade of two unit tests. What is the minimum grade that Sally must get on her final exam in order to have a class average of or above for the course, if her unit test scores are , , and

Answer

The course grade average is calculated by using Sally's three test scores and final exam. student must score at least an average of ; therefore we can write the following:

Given that the average is calculated using three test scores and a final weighted as two regular tests, we can write the following equation.

Let's use these equations to construct an inequality where we will substitute in our known values and let a variable, , equal the final score needed to earn an a or above.

Sally needs to at least score a on the final to score or above.

Compare your answer with the correct one above

Question

The mean of the set is 20. What is the mean of the set ?

Answer

To find mean, we add up the values in a set and divide by the number of terms in that set. We begin this problem with the knowledge that the mean of the first set is 20. Since that set contains five numbers, we know that its total sum must be 100 (since 100 divided by 5 is 20).

so must be 25.

Now, the only step left is to find the mean of .

These values add up to 125, and when we divide by 5, we are left with a final answer of 25.

Compare your answer with the correct one above

Question

Find the mean of the following set of numbers: 32, 23, 46, 52, 37.

Answer

To find the mean, or average, of a set of numbers, you first add all of the numbers together:

.

Then, you divide the sum by the total number of numbers, which in this set is 5 (i.e., there are 5 numbers in this set):

.

38 is the mean, or average, of this set of numbers.

Compare your answer with the correct one above

Question

Consider the following numbers:

42, 51, 62, 47, 38, 50, 54, 44

The value 48.5 represents:

Answer

First, calculate the mean. Sum the values and divide by the total number of values:

Next, determine the median. Reorder the values in ascending order:

38, 42, 44, 47, 50, 51, 54, 62

The median is the middle number. In this case, there is no "middle" number because we have an even number of values. Therefore, both 47 and 50 are the "middle". Average these numbers:

Therefore, 48.5 represents both the mean and median.

Compare your answer with the correct one above

Question

This semester, Reese must take 4 exams for his algebra class. On his first 3 exams, he scored a 73, 79, and 83. What is the minimum score he must earn on his fourth exam to get an average of 80 or higher?

Answer

To calculate the average score, you must take the sum of Reese's scores and divide it by the number of tests he took (4). To get an average of 80, the sum of Reese's scores must be 320.

The sum of his first three test scores is 235.

Thus, Reese must earn a score of 85 on his fourth test

Compare your answer with the correct one above

Question

For her calculus class, Marie has scored , , and on three of her tests so far. What is the minimum score Marie needs to receive on her 4th test in order to have an average of ?

Answer

To find the average of a set of numbers, add up the individual values and divide by the total number of values you have.

For the test scores, we can set up the following equation with x being the score on the fourth test:

Now, solve for x

Compare your answer with the correct one above

Question

Find the mean of the following set of numbers:

Answer

To find the mean of a set of numbers, you must add them all and then divide their sum by the number of total members of the set.

and there are numbers in the set, so we divide by ,

giving us a mean of .

Compare your answer with the correct one above

Question

In her last basketball games, Jo scored points, points, points, points, and points. How many points per game does she score on average?

Answer

To find the average, add up all the values you are given and divide by the number of values there are.

18 + 12 + 22 + 24 + 14 = 90, the sum of her total points.

And 90/5 = 18, which is her average.

Compare your answer with the correct one above

Question

Judy received these scores on her last four math tests:

, , ,

Her teacher calculates the final grade from the mean of five tests, which are all weighted equally. If Judy gets a on her fifth test, what will be her overall grade in the class?

Answer

To find Judy's overall grade, you must find the mean of all five test scores.

Add together all five scores:

Then divide the sum by the total number of scores:

is Judy's overall score in the class.

Compare your answer with the correct one above

Question

Jimmy's dog had 6 puppies. He weighed the puppies right after they were born. Their weights were 657 grams, 789 grams, 456 grams, 554 grams, 635 grams, and 446 grams. In grams, what was the mean weight of the puppies?

Answer

The mean of a set of numbers is the same as its average.

So then, to find the mean weight for the puppies,

Compare your answer with the correct one above

Question

Danielle tracked how much she paid per meal for the past five meals. She paid . What was the average she paid per meal?

Answer

To find the average (also known as the mean), we use the following formula:

So, for the numbers that are given in the question, we can set up this equation:

Compare your answer with the correct one above

Question

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

Answer

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 .

Compare your answer with the correct one above

Question

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

Answer

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.

Compare your answer with the correct one above

Tap the card to reveal the answer