Your SlideShare is downloading. ×
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Measuresofcentraltendency 121117004155-phpapp01
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Measuresofcentraltendency 121117004155-phpapp01

239

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
239
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
13
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. What is Central Tendency? Measures of Central Tendency: - one type of summary statistic - are measures of location within a distribu-tion - A measure that tells us the middle of a bunch of data lies - 3 most common measures of central tendency are mean, median, mode
  • 2. Importance of the Measures of Central Tendency • • • • To find representative value To condense data To make comparisons Helpful in further statistical analysis
  • 3. MEAN
  • 4. Example: The marks of seven students in a mathematics test with a maximum possible mark of 20 are given below: 15 13 18 16 14 17 12 Find the mean of this set of data values. Solution: 15
  • 5. MEDIAN • The median (mdn) of a set of data values is the middle value of the data set when it has been arranged in ascending order. That is, from the smallest value to the highest value.
  • 6. Note: • If the list has an odd number of entries, the median is the middle entry in the list after sorting the list into increasing order. Example: The marks of nine students in a geography test that had a maximum possible mark of 50 are given below: 47 35 37 32 38 39 36 34 Find the median (mdn) of this set of data values. 35
  • 7. Solution: Arrange the data values in order from the lowest value to the highest value: 32 34 35 35 36 37 38 39 47 The fifth data value, 36, is the middle value in this arrangement. .: mdn = 36 Formula:
  • 8. Note: In 32 34 35 Mdn = 5th value Mdn = 36 Mdn = 35 36 37 38 39 47
  • 9. Note: If the list has an even number of entries, the median is equal to the sum of the two middle (after sorting) numbers divided by two. Example: The marks of eight students in a math test that had a maximum possible mark of 20 are given below: 12 18 16 21 10 13 17 19 Find the median of this set of data values.
  • 10. Solution: Arrange the data values in order from the lowest value to the highest value: 10 12 13 16 17 18 19 21 The number of values in the data set is 8, which is even. So, the median is the average of the two middle values.
  • 11. MODE • For lists, the mode is the most common (frequent) value. • A data set has no mode when all the numbers appear in the data with the same frequency. • A data set has multiple modes when two or more values appear with the same frequency.
  • 12. Example: Find the mode of the following data set: 48 44 48 45 42 49 48 The mode is 48 since it occurs most often.
  • 13. Example: The test scores of 9 seventh grade students are listed below. Find the mode. 82, 92, 75 , 91, 92, 89, 95, 100, 86 The mode is 92 since it occurs most often.
  • 14. Note: • It is possible for a set of data values to have more than one mode. • If there are two data values that occur most frequently, we say that the set of data values is bimodal. • If there is no data value or data values that occur most frequently, we say that the set of data values has no mode.

×