Proportion Z Test and Intervals

Which confidence would result in a wider interval (assuming nothing else changed), 91% or 97%?

• 97%, z* is larger for higher confidence intervals

• 97%, the standard error is larger for higher confidence intervals

• 91%, z* is larger for lower confidence intervals

• 91%, the standard error is smaller for lower confidence intervals

Which of the following is an example of an interval estimate?

• point estimate 

• critical value

• confidence interval

• statistic

What is the confidence interval being calculated in the image to the left?

• 90% confidence interval

• 95% confidence interval

• 99% confidence interval

• 35% confidence interval

Which is the correct program to use on the TI-84 calculator in order to calculate confidence intervals for population proportion?

• STAT->

  TESTS->

  7: ZInterval

• STAT->

  TESTS->

  1-PropZint

• STAT->

  TESTS->

  3: 2-SampZTest

• 
  STAT->

  TESTS->

  2:T-Test

A random sample of 425 citizens of Naboo found that 34% support the Galactic Republic. A sample of 585 citizens of Tatooine found that 38% support the Galactic Republic. What test would you use to determine if the the proportions are different?

• 2 sample z-test for mean 

• 2 sample t-test for mean

• matched-pairs dependent sample t-test for mean

• 2 - proportion z test

A random sample of 425 citizens of Naboo found that 34% support the Galactic Republic. A sample of 585 citizens of Tatooine found that 38% support the Galactic Republic. What test would you use to determine if the the proportions are different?

• 2 sample z-test for mean 

• 2 sample t-test for mean

• matched-pairs dependent sample t-test for mean

• 2 - proportion z test

In a random sample of 60 shoppers chosen from the shoppers at a large mall, 36 indicated that they had been to a movie in the past month. In an independent random sample of 50 shoppers chosen from the shoppers in the downtown shopping area, 31 indicated that they had been to a movie in the past month. What significance test should be used to determine whether these data provide sufficient evidence to reject the hypothesis that the proportion of shoppers at the mall who had been to a movie in the past month is the same as the proportion of shoppers in the downtown shopping area who had been to a movie in the past month?

• One proportion z-test

• One sample z-test for a mean

• One sample t-test for a mean

• Two proportion z-test

• Two sample t-test for means

In 1975, a random sample of 1484 adult U.S. citizens was surveyed, and 193 strongly agreed with the statement, "People should take care of themselves". Then, in 1991, a survey of 1013 adult U.S. citizens showed that only 61 strongly agreed with the statement. Does this indicate that the proportion of U.S.adults who strongly agree with the given statement has dropped?

• Two-Sample Z Test for the Difference in Proportions

• Two-Sample T Test for the Difference in Means

• Matched Pairs T Test for a Mean

• One-Sample T Test for a Mean

It was found that in a sample of 90 teenage boys, 70% of them have received speeding tickets. What is the 95% confidence interval of the true proportion of teenage boys who have received speeding tickets?

• (0.61, 0.80)

• (0.591, 0.812)

• (0.584, 0.830)

• (0.65, 0.85)

In a survey of 104 students, it was found that 79 went to the homecoming game this year. Calculate a 99% confidence interval for p (true proportion of students that attended homecoming).

• (.59, .79)

• (.62, .85)

• (.60, .90)

• (.65, .87)