How to find mean - Algebra 1

The outcomes from rolling a die are {1,2,3,4,5,6}.

The mean is (1+2+3+4+5+6)/6 = 3.5.

Rolling the die six million times simply suggests that each number will appear approximately one million times. Since each number is rolled with equal probability, it doesn't matter how many times you perform the experiment; the answer will always remain the same.

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.

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.

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.

First, calculate the sum of all of the numbers.

Next, divide by the total number.

The numbers add up to 30. To find the mean, divide by the number of numbers (6) and you get a mean of 5. Mean is a fancy way of saying average.

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

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 .

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.

There are total possible outcomes ( sides on one die times sides on the other). The following are the possible outcomes that are greater than .

and

and

5 and

and

and

and

There are possible outcomes greater than , out of possible outcomes total; thus, there is a chance of rolling greater than .

Because this is an "opt-in" study, certain individuals are more likely to participate than others resulting in a selection bias.

The mean, , of a data set is the sum of the elements, , divided by the number of elements, .

We know that and . Now we can solve for .

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.

The average of the first 5 students' scores is 90, which means that the total score for these 5 students is 450. To find the total score of all 6 students, you simply add the sixth student's score of 84 to the first 5 students' total score of 450, which gives you a total score of 534 for all 6 students. To determine the average score, you must divide the total score of 534 by 6, which gives you an average score of 89.

Since they had an average score of 90, we know that their total score must have been 270 (90 multiplied by 3). We know that 2 of the scores are 94 and 92, so the third score must be , which is 84.

To determine the mean of a set of numbers, first add up all of the numbers in that set. Then divide the sum (40) by the amount of numbers in the original set (8).