Page 163 - Math Course 2 (Book 2)
P. 163
Sampling and Prediction
Mo. 11
Lesson 4 stratified random sample
a sample in which the population is divided into
similar, non-overlapping groups.
KEY CONCEPTS: A simple random sample is then selected from
each group.
1. Identify various sampling techniques.
2. Determine the validity of a sample and Students are divided into groups based on
predict the actions of a larger group. the month of their birthday. Five students
are selected from each of the 12 months.
MO. 11 - L4a biased sample
A sample that is not representative of the
Sampling Techniques population is called biased sample.
Only students who scored between who
scored between 60% – 70% on the final
Vocabulary A-Z exam are selected.
Let us learn some vocabulary
convenience sample
a sample which includes members of the
population population that are easily accessed.
The larger group from which the sample is taken is
called the population. Only students who live within 1 kilometer of
the school are selected.
All the people in the group to select from are
the population.
voluntary response sample
a sample which involves only those who want to
participate in the sampling.
Only students whose volunteer are selected.
unbiased sample
is a sample that is: systematic random sample
• representative of the larger population a sample in which the items or people are selected
• selected at random or without preference, and according to a specific time or item interval.
• large enough to provide accurate data.
One of every 5 students to enter the school
75% of all the student at the school from gate is selected.
all the grade levels are selected randomly
using a computer. Every 5 minutes, one student is selected
from those entering the gate.
simple random sample
a sample where each item or person in a
population is as likely to be chosen as any other.
Thirty students are randomly selected by a
computer based on Student ID number.
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