Ch 8 (.1/.2) quiz

A tire store manager wants to estimate the population proportion of customers who purchase snow tires in December. A random sample of customers results in a point estimate of 0.36 with a margin of error of 0.03. Construct a confidence interval from these values

• (0.335, 0.375)

• (0.33, 0.36)

• (0.33, 0.39)

• (0.36, 0.39)

• (0.30, 0.42)

A study examined the nesting behavior of northern flying squirrels in California's Teakett Forest. A 95% confidence interval for the population proportion of their nests located in whi fir trees was determined to be (0.420, 0.653). Which of the following is the best interpretati of this interval?

• If the same sampling strategy were used many times, approximately five percent of t samples would result in a sample proportion less than 0.420 or greater than 0.653.

• The probability is 0.95 that true proportion of northern flying squirrel nests in the Teakett Forest that are in white fir trees is between 0.420 and 0.653

• The true proportion of northern flying squirrel nests in white fir trees must be bet 0.420 and 0.653.

• We are 95% confident that the true proportion of northern flying squirrel nests in Teakettle Forest that are in white fir trees is between 0.420 and 0.653

• We are 95% confident that a randomly selected sample would result in a samp proportion between 0.420 and 0.653

While estimating the proportion of cell phone towers that are properly illuminated, a federal investigator performed a simulation study with 200 computer-generated random samples of the same size. For each sample, a 90% confidence interval was constructed. Which value would you expect to be captured by approximately 180 of these 200 confidence intervals?

• The sample proportion

• The sample mean

• The sample standard deviation

• The population proportion

• The population mean

A polling agency conducted a survey with a random sample of 1,000 voters from a large city who had voted in the last school board election. The agency constructed a 90% confiden interval of (0.266, 0.314) for the proportion of voters who felt the voting process was too time consuming. Which of the following statements is the best interpretation of the 90% confidence level?

• The probability is 0.90 that the confidence interval captures the proportion of voters in t sample that felt the voting process was too time consuming.

• f the agency were to take many random samples of 1,000 people and construct a confidence interval for each, 90% of them will be identical, because they were construct from samples of the same size

• The agency can be 90% confident that the sample proportion of voters in this large ci who felt the voting process was too time consuming is correct.

• The agency can be 90% confident that the true proportion of voters in this large city w felt the voting process was too time consuming is between 0.266 and 0.314

• In repeated random samples of size 1,000, approximately 90% of the confidence interva created would capture the population proportion of voters who felt the voting process was too time consuming

A sleep doctor conducted a survey with a random sample of patients with sleep disorders. The doctor constructed a 90% confidence interval of (0.55, 0.77) for the proportion of patients w always take their prescribed medication. Using the same sample, which of the following could be a 95% confidence interval?

• (0.38, 0.64)

• (0.53, 0.79)

• C) (0.57, 0.75)

• (0.60, 0.86)

• (0.68, 0.72)