Inference

Front

Hypotheses for determining if more than 50% of households gave a charitable donation last year.

Back

Front

Interpretation of 95% confidence level in a survey of 100 samples, each with 1,200 US citizens, about optimism in the economy.

Back

We would expect about 95 of the 100 confidence intervals to contain the proportion of all citizens of the United States who are optimistic about the economy.

Front

What is the appropriate method for constructing a one-sample confidence interval to estimate the population mean surface area of the species of maple leaves, and why is the method appropriate?

Back

The t-interval is appropriate, because the population standard deviation is not known.

Front

Smallest sample size for 95% confidence and 0.02 margin of error in estimating TV viewers of a program? Options: 40, 50, 100, 1700, 2500

Back

2500

Front

99% confidence interval for the proportion of all employees at the company who own an electric car, given 15 out of 500 sampled own one.

Back

Front

Which procedure is most appropriate for investigating whether an association exists between gender and the number of friends a person has on a social media Web site?

Back

A chi-square test of independence

Front

On the day before an election in a large city, each person in a random sample of 1,000 likely voters is asked which candidate he or she plans to vote for. Of the people in the sample, 55 percent say they will vote for candidate Taylor. A margin of error of 3 percentage points is calculated. Which statement is appropriate?

Back

The sample proportion minus the margin of error is greater than 0.50, which provides evidence that more than half of all likely voters plan to vote for candidate Taylor.

Front

A 90 percent confidence interval for the slope of a regression line is determined to be (-0.181, 1.529). Which statement must be true?

Back

The correlation coefficient of the data is positive.

Front

A matched-pairs t-test is NOT an appropriate way to analyze data consisting of which of the following?

• Measurements of annual income taken both before and after a two-year training course for a random sample of 100 people who took the course
• Measurements of annual income for each twin for 100 randomly selected pairs of twins
• Measurements of annual income for both individuals in pairs formed by matching 100 people from State A and 100 people from State B based on level of education
• Measurements of annual income for both individuals in pairs formed by assigning 100 people to pairs at random
• Measurements of annual income recorded for both spouses of 100 randomly selected married couples

Back

Measurements of annual income for both individuals in pairs formed by assigning 100 people to pairs at random

Front

Hypothesis to test if actual mean flight time is greater than 38 minutes.

Back