Confidence Interval Estimation with TI-84

This video tutorial demonstrates how to use the TI-84 calculator to determine a confidence interval for a population proportion. It uses a market research scenario where 500 adults are surveyed, and 421 own cell phones. The tutorial guides through entering data into the TI-84, selecting the correct test, and interpreting the results, which show a 95% confidence interval for the true proportion of adults with cell phones in the city.

What is the primary purpose of using the TI-84 calculator in this example?

• To find the median of a dataset

• To calculate the mean of a dataset

• To determine a confidence interval for a population proportion

• To perform a linear regression analysis

How many adult residents were surveyed in the market research scenario?

• 550

• 500

• 450

• 400

What is the number of successes (people who own cell phones) in the survey?

• 421

• 450

• 500

• 379

Which option should be selected on the TI-84 to calculate the confidence interval?

• Two-Prop Z Int

• One-Prop Z Int

• One-Prop Z Test

• Two-Sample T-Test

What confidence level is used in this example?

• 95%

• 90%

• 85%

• 99%

What is the lower bound of the confidence interval obtained from the TI-84?

• 0.830

• 0.820

• 0.810

• 0.800

What is the upper bound of the confidence interval obtained from the TI-84?

• 0.884

• 0.894

• 0.874

• 0.864

What does the sample proportion (p-hat) represent in this context?

• The proportion of the sample that owns cell phones

• The margin of error

• The total number of people surveyed

• The confidence level used

What does a 95% confidence interval imply about the population proportion?

• It means 95% of the population owns cell phones

• It means we are 95% confident the interval contains the true proportion

• It means the true proportion is exactly 95%

• It means the interval is 95% of the sample size

How often would confidence intervals constructed in this way contain the true population proportion?

• 100% of the time

• 50% of the time

• 75% of the time

• 95% of the time