Basic Arithmetic : Basic Arithmetic
Study concepts, example questions & explanations for Basic Arithmetic
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Example Questions
Example Question #2 : Basic Statistics
The mean of the set 
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 
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.
Example Question #281 : Basic Arithmetic
Find the mean of the following set of numbers: 32, 23, 46, 52, 37.
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.
Example Question #12 : Mean
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?
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
Example Question #282 : Basic Arithmetic
Consider the following numbers:
42, 51, 62, 47, 38, 50, 54, 44
The value 48.5 represents:
The mean
Both the mean and the median
The median
Neither the median nor the mean
Both the mean and the median
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.
Example Question #283 : Basic Arithmetic
Find the mean of the following numbers:
150, 88, 141, 110, 79
88
113.6
71
141
110
113.6
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.
Example Question #284 : Basic Arithmetic
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?
71
90
98
95
82
98
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 #285 : Basic Arithmetic
The mean of the following set is 8. What is 
Cannot be determined
8
9
2
1
1
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 #17 : Mean
If the average of 
If the average of 
We also know the average of 
The expression in the numerator represents the sum. By cross-multiplying, we get
Example Question #12 : Basic Statistics
If the average of 
To find the average of all the numbers, we need to find the sums from each average. Since the average of 
The average of 
Then, the total sum is 
So to find average, we do 
Example Question #13 : Basic Statistics
Find the mean for the following set of numbers:
The mean is the same as the average. To find the mean, use the following formula:
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