A random sample of 350 registered voters found that 196 support a proposed transit tax, and a 95 percent confidence interval for the proportion of all registered voters who support it was computed to be 0.508 to 0.612. Which of the following conclusions about majority support is best supported by this interval?
constructing a confidence interval for a population proportion
Review constructing a confidence interval for a population proportion for AP Statistics and try 2 free AP-style practice questions. 16 questions on this topic in AP Statistics · Unit 3 · Inference for Categorical Data: Proportions.
6 topics97 multiple-choice8 free-response
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A simple random sample of 120 households finds that 42 subscribe to a streaming service (). A confidence interval is . Assuming conditions are met, which of the following actions would produce a confidence interval with a smaller margin of error and a lower confidence level than ?
Sample free-response question
A town tests samples from its water supply. Each sample is either contaminated or not. The safe standard is that at most 5 percent of samples are contaminated. The town tests H0: p = 0.05 against Ha: p > 0.05 every month.
(a) Describe a Type I error and a Type II error in this context.
(b) Which error is more serious for the town's residents? Explain.
(c) Should the town use a significance level of 0.01 or 0.10? Explain using part (b).
(d) Describe two ways the town could increase the power of its test.
(e) The test has power 0.70 if the true rate is 8 percent. Interpret this value.
14 more questions on this topic
Full practice for AP Statistics · Unit 3 · Inference for Categorical Data: Proportions: timed tests, step-by-step explanations for every answer, and AI grading for free-response questions.
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Answer, then see why
The price of gasoline rises 10% and the quantity demanded falls 5%. What happens to total revenue?
Not quite. The answer is B.
Why the other options are wrong
AI grading for free-response
Write your FRQ answer and get it scored point by point against the AP rubric, with the line from your answer that earned or missed each point.
Question 13 / 4 pts
Part a1 / 1 pts
Point 1: Earned
Grader confidence 94% sureReason: Correctly identifies demand for gasoline as inelastic.
Evidence: "The price of gasoline rises and the quantity falls only a little."
Part b2 / 3 pts
Point 1: Earned
Grader confidence 91% sureReason: Graph shows relatively inelastic demand.
Evidence: Draws a steep demand curve.
Point 2: Earned
Grader confidence 88% sureReason: Correct new equilibrium price.
Evidence: Shifts supply left, P1 → P2.
Point 3: Not earned
Grader confidence 82% sureReason: With inelastic demand, a price increase raises total revenue.
Evidence: "Revenue goes down."