Measures of Central Tendency
Another name for the mean is ________ and how do you calculate it?
The average. To calculate the mean you add up the set of numbers and divide by the total number of values
What is the range?
15, 17, 11, 20, 10, 18, 20, 19, 5
15
In a box plot, the line inside the box that represents the median of the data is also known as this.
What is standard deviation?
The distance of a set of data points from the mean
I have a dollar, and you have a dollar. If we each give a quarter to a friend, how many dollars do we each have left?
75 cents
(Each person has a dollar, and after giving away a quarter, they both have 75 cents each.)
Find the mode and define it.
12, 13, 13, 15, 10, 11, 11, 11, 10, 9
11
Mode- the number that appears the most or has the highest frequency
Is this considered a statistical or non-statistical question?
What is the average height of students in your class?
Statistical – It involves collecting data from multiple students to calculate the average.
In a box plot, this area of the box represents the middle 50% of the data.
The Interquartile Range (IQR)
Set A: 3, 4, 5, 6, 2, 3, 4
Set B: 3, 6, 8, 9, 1, 9, 1
Which data set would have the smaller standard deviation? How can you tell? (no calculations needed)
Set A because the numbers are closer together
What letter comes once in a minute, twice in a moment, but never in a thousand years?
the letter M
Find the median and define it.
On a state licensing test, Jean and her friends got the following scores: 65, 78, 63, 78, 97, 42, and 53. What was their median score?
65
Median- the value in the middle
Is this considered a statistical or non-statistical question?
How many people live in Paris?
Non-statistical – This is asking for a specific number (a fact), not an analysis of a group or trend.
Given the 5-number summary:
Minimum = 12, Q1 = 20, Median = 35, Q3 = 50, Maximum = 75,
What is the Interquartile Range (IQR)?
30
(IQR = Q3 - Q1 = 50 - 20 = 30)
A normal distribution has a mean of 8 and a standard deviation of 2. The value that is 2 positive standard deviations away from the mean is this_______
12
What is the next number in the sequence: 1, 4, 9, 16, 25, ?
36
(These are perfect squares: 1², 2², 3², 4², 5²... so the next number is 6² = 36.)
There are three women in Jenny's carpool. Their ages are 52 years, 29 years, and 39 years. What is the average age of the women in the carpool?
40
What is the most common favorite ice cream flavor among 9th graders in the United States?
Is this a statistical or non-statistical question?
Statistical – It involves collecting and analyzing data from a group of 9th graders.
Minimum = 10, Q1 = 18, Median = 25, Q3 = 40, Maximum = 65,
What is the range of this data?
55
(Range = Maximum - Minimum = 65 - 10 = 55)
A normal distribution has a mean of 15 and a standard deviation of 3. The value that is 3 negative standard deviations away from the mean is this______.
6
I am a number. If you subtract me from 100, the result is the same as if you subtract 10 from me. What number am I?
55
(100 - 55 = 45, and 55 - 10 = 45, so both give the same result.)
Find the median.
12, 13, 13, 15, 10, 11, 11, 11, 10, 9
How many continents are there on Earth?
Is this a statistical or non-statistical question?
Non-statistical – It asks for a factual answer, not based on any data analysis.
There are 7 continents on Earth. They are: Asia, Africa, North America, South America, Antarctica, Europe, Australia (sometimes referred to as Oceania when including the Pacific islands)
Find the 5 number summary.
Dataset of Test Scores (out of 100):
72, 85, 93, 88, 65, 77, 91, 84, 78, 95
A data set with a standard deviation of 9 has a variance of what?
81
I have keys but open no locks. I have space but no room. You can enter but never go outside. What am I?
A keyboard
(A keyboard has keys, spacebar, and the "enter" key but no actual locks or rooms.)