Okay guys, here i posted more examples about the
measures of central tendency :)
Example No.1
Find the mean, median and mode for the following data:
5, 15, 10, 15, 5, 10, 10, 20, 25, 15
(You will need to organize the data.)
5, 5, 10, 10, 10, 15, 15, 15, 20, 25
Mean: Sum of all data ÷ No.of terms
130 / 10 = 13 (ans)
Median: 5, 5, 10, 10, 10, 15, 15, 15, 20, 25
** Listing the data in order is the easiest way to find the median.
The numbers 10 and 15 both fall in the middle.
Average these two numbers to get the median.
10 + 15 =12.5 / 2
= 6.25 (ans)
Mode: Two numbers appear most often: 10 and 15.
There are three 10's and three 15's.
In this example there are two answers for the mode.
Example No.2
For what value of x will 8 and x have the same mean (average) as 27 and 5?
First, find the mean of 27 and 5:
27 + 5 = 16 / 2
Now, find the x value, knowing that the average of x and 8 must be 16:
x + 8 ÷ 2 = 16
32 = x + 8 cross multiply
-8 - 8
= 24 (ans)
Example No.3
On his first 5 biology tests, Bob received the following scores: 72, 86, 92, 63, and 77. What test score must Bob earn on his sixth test so that his average (mean score) for all six tests will be 80? Show how you arrived at your answer.
Possible solution:
Set up an equation to represent the situation. Remember to use all 6 test scores:
72 + 86 + 92 + 63 + 77 + x = 80 / 6
cross multiply and solve: (80)(6) = 390 + x
480 = 390 + x
- 390 -390
90 = x
Bob must get a 90 on the sixth test.
Example No.4
The mean (average) weight of three dogs is 38 pounds. One of the dogs, Sparky, weighs 46 pounds. The other two dogs, Eddie and Sandy, have the same weight. Find Eddie's weight.
Let x = Eddie's weight ( they weigh the same, so they are both represented by " x ".)
Let x = Sandy's weight
Average: sum of the data divided by the number of data.
x + x + 46 = 38 cross multiply and solve
3(dogs)
(38)(3) = 2x + 46
114 = 2 x + 46
68 = 2x
2 2
34 = x Eddie weighs 34 pounds.
No comments:
Post a Comment