• Satisfying Margins of Error Step-by-step Lesson- How many people do you need to survey to have your acceptable level of error?
• Guided Lesson - Determining confidence levels and modeling it can be tough, if you see it in the numbers.
• Guided Lesson Explanation - Some answers are just common sense.
• Population Identification Types of Survey Sampling Worksheet - Some neat scenarios are given here.
• Matching Worksheet - It is all about find the n variable.

• Answer Keys - These are for all the unlocked materials above.

Homework Sheets

I always found this skill fascinating, in terms of the applications.

• Homework 1 - A survey was about to be conducted on the support of wearing school uniforms. The researchers wanted to insure a 3.5 margin of error with a confidence level of 85%. It was found that 20% of people support school uniforms. What is minimum number of people that would need to be surveyed to reach the margin of error level presented?
• Homework 2 - A large automotive parts wholesaler needs an estimate of the mean life it can expect from a windshield wiper blade with a 99% confidence level. The accepted theory was that wipers had a life span of 18 months. This study found the mean life to be 10 months. What sample size must be surveyed to reveal this level of confidence?
• Homework 3 - A survey was looking for the number of T-shirts a family wears over the course of their entire lives. What would the sample size need to be to have a 99% confidence and accuracy of 3,130 with a 2.1 margin of error? A standard deviation of 6.2 is expected.

Practice Worksheets

This is where data really can help large organizations make decisions.

• Practice 1 - The ACT scores of students had margin of error 4.32 with a confidence level of 95%. Initially the scores estimated the mean on the test to be 45%. The scores had a standard deviation of 28. What was sample size surveyed?
• Practice 2 - Find the sample size of a survey that has a margin of error of 40, a confidence interval 99%, and an outcome of 70%. The data is binomial and you are taking a sample proportion.
• Practice 3 - Find the margin of error with a sample mean of 2.34, a confidence interval 90%, and an outcome of 60%. The data is binomial and you are taking a sample proportion.

Math Skill Quizzes

I focused more on the data here. We haven't seen many deep thought questions like the practice sheets on national exams.

• Quiz 1 - The data presented is binomial and you are taking a sample proportion.
• Quiz 2 - Find the margin of error with a sample mean of 15.24, a confidence interval 99%, and an accuracy of 40%.
• Quiz 3 - Find the final value of n.

What are Sample Surveys?

The word sample survey is very common in statistics. It refers to the process of selecting a sample of observations or elements chosen from a population of interest using the probability-based sample design to conduct a survey. We this to better understand the population of interest. It can help the population answer profound questions that otherwise might escape them. The survey can be conducted with many different techniques, but the process most commonly involves using a questionnaire as a tool to gather the information.

More often than not, certain processes in sample surveys are used to improve the precision and control the cost of process when collecting the data. The methods used in sample surveys tend to introduce complexity in the analysis process, which is required to be taken into consideration to produce impartial estimates. The method of collecting this data must be well thought out to increase the reliability and validity of the data. When collecting data for a survey there are many different methods for doing so. It can be in form of a paper survey, it could be online, or even an informal interview. The method that is chosen often reflects the population that is the center of the study, and which fits them the best.

The samples of a survey can be divided into braid categories of 1) probability samples or 2) super samples. It is one method or technique most researchers or statisticians use in their research to find a relationship between two or more variables. The samples taken for the survey are either randomly selected or self-selected. The most common advantage of sampling is its ease of use and accurate representation of large population.

Once all the data from the surveys is collected and analyzed, the body that is holding the study can often gain substantial insights into the population that they are studying. An important thing to remember is that being able to confirm anything from research matters. Whether it is that something works or that something does not work. If we invalidate things through research and share our results it encourages researchers to look in other directions and find out what does work.