Sampling & MOE (after 3.4 HW)

Which of the following statements about margin of error is true?

• A larger margin of error indicates a more precise estimate.

• Margin of error is not affected by the sample size.

• A smaller sample size results in a smaller margin of error

• Margin of error provides a range within which the true population parameter is likely to fall.

Most people can roll their tongues, but many can't. Suppose we are interested in determining what percent of people can roll their tongue and find from a sample that between 72.4% and 83.6% of them can roll their tongues. The center of this interval is ____%.

Most people can roll their tongues, but many can't. Suppose we are interested in determining what percent of people can roll their tongue and find from a sample that between 72.4% and 83.6% of them can roll their tongues. The margin of error is ____%.

How does a larger sample size typically impact sampling variability?

• It increases the accuracy of the population parameter

• It does not affect sampling variability.

• It leads to more biased results in the sample

• It decreases sampling variability.

A recent Gallup poll conducted telephone interviews with a random sample of 1000 adults aged 18 and older. Of these, 37% said that football is there favorite sport to watch on TV. The margin of error for this estimate is 3.1 percentage points. Interpret this margin of error.

A recent Gallup poll conducted telephone interviews with a random sample of 1000 adults aged 18 and older. Of these, 37% said that football is there favorite sport to watch on TV. The margin of error for this estimate is 3.1 percentage points. Would you be surprised if a census revealed that the population proportion was 0.50?

• No, because 1000 people is a good sample size to use.

• No, because 50% is included in the interval created by the estimate and margin of error.

• Yes, because 50% is not included in the interval created by the estimate and margin of error

• Yes, because it could happen by chance alone. There's a 50% chance that football is a person's favorite sport to watch.