Central tenDANCiEs
Find the mean in the following data set: 1, 2, 3, 4, 5, 6
3.5
What is x?
3x=24
x=8
The mode in the following data set: 55, 66, 68, 77, 77, 78, 78, 78, 90, 100, 100
78
A type of survey that questions only a portion of the population.
Sample survey.
Find the median in the following data set: 1, 4, 6, 8, 19, 22, 25
8
You find me by adding up all of the numbers and then dividing by the number of data points.
Mean
Convert 16m to mm
16,000 mm
Define: MODE
What is the measure of central tendency that identifies the number that repeats the most often in a data set.
What is the mode of this data set: 0, 2, 2, 3, 4, 5, 6, 8 ?
2
To calculate the median in a data set with an even number of data points.
Add the two middle scores up and divide them by two.
If the results on your 4 tests were as follows: 4%, 86%, 86%, 90%
Which measure of central tendency (mean, median range OR mode) would you rather the teacher NOT use to calculate your report card grade? WHY?
The mean.
Mean = 66.5%
Mode = Median = Range = 86%
The simplest way to find the area of a rectangle.
length times height
True or False: Finding the mode of the class' test scores can always help a teacher know if their test was fair.
False.
If I survey 30 people walking out of No Frills shopping centre about their favourite place to shop for groceries, what is the disadvantage of the data I have collected.
The data is bias. Most (or all) shoppers will say No Frills is their favourite shopping centre.
A data set with 5 score that has a median of 5, and range of 5.
0, 3, 5, 5, 5
I change the most when outlying numbers are introduced to the data set.
The mean
3 types of angles
Acute Angle
Right Angle
Obtuse Angle
Straight Angle
Reflex Angle
A data set with 8 values where the mode is 3, the median is 3, and the range is 3. It must have at one number that is not 3.
1, 1, 2, 3, 3, 3, 3, 4
Ways to collect data
Survey
Questionnaire
Observation
Interviews
Other Data
I am a measure of central tendency that is always stuck in the middle.
Median
The mean number of letters in the following people's names: Frankie Gaby Jada Umma Ysaline Diego Alex
5
On a flight:
5% of people flew first class and
15% of people flew business class.
If 160 people flew economy class, how many people flew first class?
80% = 160 people
1% = 2 people
5% = 10 people
Change one score only to make the range 60. List your new scores but the Mode and Median must stay the same.
10, 20, 30, 40, 50, 70, 80, 80, 80
20, 20, 30, 40, 50, 60, 70, 80, 80
When you question a portion of the population that may not best reflect the population's opinion.
A biased sample
These are Tav's cross-country race scores (in minutes): 0.5, 1.3, 1.4, 5.7, 5.7 Which measure of central tendency would give him the best score? why?
The median, because the mode is of the highest numbers (which is a bad score) and the extreme numbers will result in a higher mean score.