Margin of Error and Confidence Level

A study by the department of education in a certain state found that there was a mean SAT score of 534 with a margin of error of 20.

Create a confidence interval for the true mean.

• (534, 554)

• (514, 534)

• (514, 554)

A study by the department of education in a certain state found that there was a mean SAT score of 534 with a margin of error of 20.

Which score would fall outside the confidence interval?

• 505

• 530

• 550

• 553

A survey estimates that 45% of voters favor candidate A with a margin of error of 4%. What is the confidence interval for the proportion of voters who favor candidate A?

• (0.41, 0.49)

• (0.39, 0.51)

• (0.43, 0.47)

• (0.45, 0.49)

If the confidence interval for a population mean is (20, 40) and the margin of error is 10, what is the sample mean?

• 20

• 30

• 40

• 50

• 95% of all American households own 2 or more TVs.

• We can be 95% confident that between 72% and 76% of all American households own 2 or more TVs.

• We can be 95% confident that 74% of American households own 2 or more TVs.

• In our sample, somewhere between 72% and 76% of American households own 2 or more TVs.

A random sample of 692 adults revealed that 54% stream Netflix. If p hat = .54, what is the margin of error in this sample?

A sample size of n = 64 is drawn from a population whose standard deviation is σ = 5.6.

Find the margin of error for a 99% confidence interval for µ.

• 1.799

• 1.798

• 1.803

A large sample has mean of 7.1 and Standard Error of 2.3.

Construct a 90% Confidence Interval for the population mean µ (to two decimal places).

• (3.32, 10.88)

• (3.8, 7.1)

• (3.3, 10.9)

• (3.3165, 10.8835)

An IQ test was given to a simple random sample of 75 students at a certain college. The sample mean score was 105.2. Scores on this test are known to have a standard deviation of 10. It is desired to construct a 90% confidence interval for the mean IQ scores of the students at the college. Find the Margin of Error to two decimal places.

• 1.90

• 1.89

• 1.899

• 1.99

A population has a standard deviation of σ = 17.3. How large of a sample must be drawn so that a 95% confidence interval for µ will have a Margin of Error equal to 1.4?

• 586.6

• 587

• 586

• 585