Trick of the Day - Arithmetic Mean
Page 1 of 1
Trick of the Day - Arithmetic Mean
This trick saves some time on questions which ask for you to find the average of two numbers
ex.1 - Find the average of 25, 27, and 35
1. First, think of a number which is a multiple of ten which could be the average (let's say 30 in our case)
2. Secondly, subtract that number from each of the original numbers (25-30 = -5, 27-30 = -3, 35-30 = 5)
3. Add together the above answers (-5-3+5 = -3)
4. Divide the number by the number of terms (-3/3 = -1)
5. add the resulting numer(-1) and the approximation together (-1 + 30 = 29) and you have your answer
Find the average of 25, 27, and 35 = 29
Keep in mind that this trick works for more than just three numbers, as stated above in the steps
Now, try some practice problems
1. AVG(19, 21, 25)
2. AVG(12, 33, 25)
3. AVG(19, 21, 43, 34)
4. AVG(62, 63, 58)
5. AVG(85, 80, 97)
6. AVG(27, 31, 25)
7. AVG(11, 12, 13, 9, 7, 15)
8. AVG(99, 101, 110)
9. AVG(118, 121, 125)
10. AVG(120, 121, 125, 121, 115)
11. AVG(131, 135, 125, 140)
12. AVG(1435, 1351)
ex.1 - Find the average of 25, 27, and 35
1. First, think of a number which is a multiple of ten which could be the average (let's say 30 in our case)
2. Secondly, subtract that number from each of the original numbers (25-30 = -5, 27-30 = -3, 35-30 = 5)
3. Add together the above answers (-5-3+5 = -3)
4. Divide the number by the number of terms (-3/3 = -1)
5. add the resulting numer(-1) and the approximation together (-1 + 30 = 29) and you have your answer
Find the average of 25, 27, and 35 = 29
Keep in mind that this trick works for more than just three numbers, as stated above in the steps
Now, try some practice problems
1. AVG(19, 21, 25)
2. AVG(12, 33, 25)
3. AVG(19, 21, 43, 34)
4. AVG(62, 63, 58)
5. AVG(85, 80, 97)
6. AVG(27, 31, 25)
7. AVG(11, 12, 13, 9, 7, 15)
8. AVG(99, 101, 110)
9. AVG(118, 121, 125)
10. AVG(120, 121, 125, 121, 115)
11. AVG(131, 135, 125, 140)
12. AVG(1435, 1351)
Ani- Vice-President
- Number of posts : 236
Age : 32
Location : Kanto
Registration date : 2008-05-02
Similar topics
» Trick of the Day - Multiplication by 25, 50, 75, 125
» Trick of the Day - Sum of Fibonacci
» Trick of the Day - Squaring numbers between 41 and 59
» Trick of the Day - Things to memorize
» Trick of the Day - Adding Fractions in the Form a/b + b/c + c/d
» Trick of the Day - Sum of Fibonacci
» Trick of the Day - Squaring numbers between 41 and 59
» Trick of the Day - Things to memorize
» Trick of the Day - Adding Fractions in the Form a/b + b/c + c/d
Page 1 of 1
Permissions in this forum:
You cannot reply to topics in this forum