Vocabulary
Measures of Center
Data
100
The whole group being studied
What is population?
100
Find the median:
4, 4, 3, 9, 5
4
100
A school plans to start selling snacks at their basketball games. They want to know which snacks would be most popular.
What is the population for the school's question?
Basketball game attendees
200
Small group selected randomly from a population
What is random sample?
200
Find the mean:
8, 4, 5, 8, 5, 4, 8
6
200
25% of your 100 person sample like chocolate ice cream. How many people is that?
What is 25?
300
The middle number when the data is put in order
What is median?
300
Find the median:
10, 13, 11, 13, 13
13
300
Here is a dot plot showing how many books are read by each student per month.
C
400
the balance point or average
What is mean?
400
Which measure of center (mean or median) would work best for this data? Now find it.
Median - 50
400
A school plans to start selling snacks at their basketball games. They want to know which snacks would be most popular.
Give an example of a sample the school could use to help answer their question.
Answers vary
500
the measure of center you should use when the data is very spread out or has lots of outliers
What is the median?
500
Which measure of center (mean or median) would work best for this data? Now find it.
Mean - 2.75
500
The school bookstore surveyed a random sample of 10 students on whether they prefer to use a metal or plastic pen. Here were the results: metal, metal, metal, plastic, plastic, metal, plastic, plastic, plastic, plastic.
a. Estimate the proportion of all students that prefer to use a metal pen.
b. If there are 200 students, how many would prefer a pen?
a. 0.4 or 40%
b. 80 students