Mr. Rogers - AP Statistics Objectives
 Unit Plan Practice Test Practice Test Answers
 AP Statistics Test Errors and Hypothesis Testing For a two tailed test with a p=.02, What is the area under the curve associated with p in one of the tails? Area = 0.01 If a confidence interval is tripled, what is the effect on the margin of error? tripled If the sample size is increased by a factor of 16, what is the effect on the margin of error? 1/4 times original ME If the confidence level is changed from 90% to 95% what is the effect on the margin of error? (1.96 / 1.64) times ME or a 19% increase in ME What conditions must be met in order to use a t-test? SRS, population approximately normally distributed For a given test of statistical significance alpha = .02 and the p-value = .025. What can you conclude? There is not a statistically significant reason to reject the null hypothesis Juan obtains a p-value = .018 in his significance test. How should he interpret it? There is an 1.8% probability of getting a value of the test statistic as extreme or more extreme than the one obtained. A two tailed quality assurance test has an alpha = 5%. What is the probability of a type I error?  5% Which hypothesis is assumed to be true when evaluating the probability of a type I error?  the null hypothesis What is the sum of the probability of a type I and type II error for a given set of circumstances? Unknown What is the sum of the probability of a type II error and power for a given set of circumstances? 1.00 When is a pooled t-test used? When the standard deviations of the 2 samples are considered to be equal In the American justice system, the presumption of innocence until proven guilty can be called the _________________. null hypothesis For a hypothesis test beta = 10%. What is the power of the test? 90% Martha plans a survey and wants a margin of error of 2% with a confidence level of 95%. What is the minimum sample size she should use? n = 2401 Based on a survey of 1600 people, Bob finds that 60% will vote for the purple party. Construct a 95% confidence interval for the data. CI = 0.6 ± 1.96 [ .6 (1-.6))/ 1600]^0.5 or .6 ± 0.24 Based on sample of 1000, SC voters vote purple 45% of the time while based on a sample of 1200 voters, GA voters vote purple 49% of the time. Construct a 90% confidence interval for the difference between the two groups. (- 0.075 to -0.0049) A sample of Martha's coconuts has an average weight of 1.3 lb with a sample size = 12 and s = 4. A sample of Bob's coconuts has an average weight of 1.5 lb with a sample size = 10 and s = 3. Are Bob's coconuts bigger than Martha's? p = 44.7% Create a 80% confidence interval for the difference between Bob's and Martha's coconuts. (-2.18 to 1.78) What does the central limit theorem tell us about the effects of sample size on the sampling distribution? As sample size increases, the sampling distribution narrows and looks more like a normal distribution What 2 conditions must be true to use the normal approximation of the binomial? np >= 10, n(1-p) >= 10