<< Chapter < Page Chapter >> Page >

Try it

You are going to use the random number generator to generate different types of samples from the data.

This table displays six sets of quiz scores (each quiz counts 10 points) for an elementary statistics class.

#1 #2 #3 #4 #5 #6
5 7 10 9 8 3
10 5 9 8 7 6
9 10 8 6 7 9
9 10 10 9 8 9
7 8 9 5 7 4
9 9 9 10 8 7
7 7 10 9 8 8
8 8 9 10 8 8
9 7 8 7 7 8
8 8 10 9 8 7

Instructions: Use the Random Number Generator to pick samples.

  1. Create a stratified sample by column. Pick three quiz scores randomly from each column.
    • Number each row one through ten.
    • On your calculator, press Math and arrow over to PRB.
    • For column 1, Press 5:randInt( and enter 1,10). Press ENTER. Record the number. Press ENTER 2 more times (even the repeats). Record these numbers. Record the three quiz scores in column one that correspond to these three numbers.
    • Repeat for columns two through six.
    • These 18 quiz scores are a stratified sample.
  2. Create a cluster sample by picking two of the columns. Use the column numbers: one through six.
    • Press MATH and arrow over to PRB.
    • Press 5:randInt( and enter 1,6). Press ENTER. Record the number. Press ENTER and record that number.
    • The two numbers are for two of the columns.
    • The quiz scores (20 of them) in these 2 columns are the cluster sample.
  3. Create a simple random sample of 15 quiz scores.
    • Use the numbering one through 60.
    • Press MATH. Arrow over to PRB. Press 5:randInt( and enter 1, 60).
    • Press ENTER 15 times and record the numbers.
    • Record the quiz scores that correspond to these numbers.
    • These 15 quiz scores are the systematic sample.
  4. Create a systematic sample of 12 quiz scores.
    • Use the numbering one through 60.
    • Press MATH. Arrow over to PRB. Press 5:randInt( and enter 1, 60).
    • Press ENTER. Record the number and the first quiz score. From that number, count ten quiz scores and record that quiz score. Keep counting ten quiz scores and recording the quiz score until you have a sample of 12 quiz scores. You may wrap around (go back to the beginning).
Got questions? Get instant answers now!

Determine the type of sampling used (simple random, stratified, systematic, cluster, or convenience).

  1. A soccer coach selects six players from a group of boys aged eight to ten, seven players from a group of boys aged 11 to 12, and three players from a group of boys aged 13 to 14 to form a recreational soccer team.
  2. A pollster interviews all human resource personnel in five different high tech companies.
  3. A high school educational researcher interviews 50 high school female teachers and 50 high school male teachers.
  4. A medical researcher interviews every third cancer patient from a list of cancer patients at a local hospital.
  5. A high school counselor uses a computer to generate 50 random numbers and then picks students whose names correspond to the numbers.
  6. A student interviews classmates in his algebra class to determine how many pairs of jeans a student owns, on the average.

a. stratified; b. cluster; c. stratified; d. systematic; e. simple random; f.convenience

Got questions? Get instant answers now!
Got questions? Get instant answers now!

Try it

Determine the type of sampling used (simple random, stratified, systematic, cluster, or convenience).

A high school principal polls 50 freshmen, 50 sophomores, 50 juniors, and 50 seniors regarding policy changes for after school activities.

stratified

Got questions? Get instant answers now!

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Introductory statistics. OpenStax CNX. May 06, 2016 Download for free at http://legacy.cnx.org/content/col11562/1.18
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Introductory statistics' conversation and receive update notifications?

Ask