Understanding Margin of Error

What does the margin of error measure in a survey?

• How large the sample size is

• The range where the true population value likely falls

• The difference between two surveys

• The confidence level of the survey.

How do you calculate a confidence interval?

• Multiply the sample estimate by the margin of error

• Divide the sample estimate by the confidence level

• Subtract the population mean from the sample mean

• Add and subtract the margin of error from the sample estimate.

If a survey finds 45% support with a ±3% margin of error, what is the confidence interval?

• 42% to 48%

• 40% to 50%

• 44% to 46%

• 43% to 47%

Why does a larger sample size lead to a smaller margin of error?

• It decreases the number of people surveyed

• It increases variability in responses

• It reduces uncertainty and improves accuracy

• It changes the confidence level

What happens to the margin of error if the confidence level increases?

• It decreases

• It stays the same

• It disappears

• It increases

A survey estimates that 70% of people prefer iced coffee, with a ±5% margin of error. What does this mean?

• Between 60% and 80% of people prefer iced coffee

• Between 65% and 75% of people prefer iced coffee

• Exactly 70% of people prefer iced coffee

• The survey results are incorrect.

A poll of 1,200 voters has a margin of error of ±4%, while a poll of 10,000 has a margin of error of ±2%. Why?

• A larger sample reduces the margin of error

• The second poll used a different survey question

• Both polls should have the same margin of error

• A smaller margin of error means a less reliable survey.

A survey estimates 38% of students use online learning, with a ±6% margin of error. What is the lowest % in the range?

• A) 44%

• B) 38%

• C) 32%

• D) 50%

If a survey's margin of error is ±2% instead of ±5%, what does this mean about the results?

• A) The survey is less precise

• B) The sample size is likely larger

• C) The sample size is likely smaller

• D) The confidence interval is wider.

Why is the margin of error important in interpreting survey results?

• It helps estimate how close the sample result is to the true population

• It ensures that the sample result is always correct

• It eliminates the need for larger sample sizes

• It tells us exactly how many people were surveyed.