Understanding Margin of Error

Miss Smith explains the concept of margin of error, its definition, and its importance in statistics. She introduces formulas to calculate the margin of error and sample size, and demonstrates these calculations with examples. The video covers how to find the true population interval and how to determine the necessary sample size for a desired margin of error.

What is the margin of error?

• The exact number of errors in a survey

• A small amount allowed for miscalculation or change of circumstances

• A fixed percentage of errors in any study

• A large amount of error in a survey

What does 'n' represent in the formulas discussed?

• The population mean

• The margin of error

• The sample size

• The number of errors

How do you calculate the margin of error (MOE) using the sample size (n)?

• MOE = sqrt(n) / 1

• MOE = 1 / sqrt(n)

• MOE = 1 / n

• MOE = n / 1

What is the formula to determine the sample size if the margin of error is known?

• n = 1 / MOE

• n = (1 / MOE)^2

• n = sqrt(MOE)

• n = MOE^2

In the example, what is the margin of error when 1,000 people are surveyed?

• 3.2%

• 2.5%

• 4.1%

• 1.8%

What is the true population interval if 63% of people prefer Coke with a margin of error of 3.2%?

• 59.8% to 66.2%

• 60.0% to 66.0%

• 61.0% to 65.0%

• 58.5% to 67.5%

How do you convert a decimal to a percentage?

• Move the decimal point one place to the left

• Move the decimal point two places to the right

• Move the decimal point one place to the right

• Move the decimal point two places to the left

How many people need to be surveyed to achieve a margin of error of ±2%?

• 1,000

• 1,500

• 2,500

• 2,000

What happens to the margin of error as the sample size increases?

• It decreases

• It stays the same

• It fluctuates randomly

• It increases

What is the margin of error if the sample size is 2,500?

• 1.5%

• 2.0%

• 3.0%

• 2.5%