questions 3

# questions 3 - STA 2023 Practice Questions Final Exam What...

This preview shows pages 1–4. Sign up to view the full content.

STA 2023 Practice Questions Final Exam What you need to know: General Format for Confidence Interval – estimator +/- (t or z) est. standard error General Format of Test Statistic -- # () o estimator from H to rz estimate of stderr = Table given to you on the test: STATISTICAL INFERENCE TABLE: Case parameter estimator standard error Sampling Distribution one mean µ x n s t (n-1) Mean of matched pairs dif. d d x d s n t (n-1) difference of two independent means 2 1 2 1 x x 2 2 2 1 2 1 n s n s + t with conservative df = smallest of (n 1 -1) and (n 2 -1) one proportion p p ˆ CI: ˆˆ (1 ) p p n ST: n p p ) 1 ( 0 0 z difference of two independent proportions 2 1 p p 2 1 ˆ ˆ p p CI: 112 2 12 ˆˆˆˆ ) ) p pp p nn −− + ST: + 2 1 1 1 ) ˆ 1 ( ˆ n n p p z McNemar YN NY TS NY = + OR NY YN TS NY = +

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Questions 1 – 4 An education researcher has developed a new technique to teach Spanish to high school students. To prove this new method is better, she will teach two groups of students for an entire semester, one with the new method and one with the standard method used today in high schools. She wishes to obtain 12 sets of identical twins, 24 people total, and split the twins up so that one of each twin is in Class 1, which will receive the new technique, and one is in Class 2, which will receive the old technique. At the end of the semester both classes will take a standardized exam and the results will be compared. 1. What method should be used to analyze this data? a) one mean b) two independent means c) comparing means of dependent samples d) two independent proportions 2. What should our hypotheses be to test if your new method is better than the old method? a) H 0 : µ 1 −µ 2 = 0 vs. H A : µ 1 −µ 2 < 0 b) H 0 : µ D = 0 vs. H A : µ D < 0 c) H 0 : µ 1 −µ 2 = 0 vs. H A : µ 1 −µ 2 > 0 d) H 0 : µ D = 0 vs. H A : µ D > 0 3. What distribution would you use to look up the p-value for this test of hypothesis? a) t(11) b) t(12) c) t(23) d) Z 4. Suppose we collect the data from this experiment and we find a p-value of 0.009. Which of the following is our conclusion at any reasonable alpha level? a) There is not evidence of a difference among the two educational methods. b) There is evidence that the old method is better than the new method. c) There is evidence that the new method is better than the old method. d) We cannot determine without more information.
Questions 5-7 use the following modifications to the above scenario. Unable to obtain the 12 sets of twins to conduct the experiment, the researcher has to use two existing Spanish classes at a local high school, one with 12 students and the other one with 11 students. 5. What method should be used to analyze this data? a) one mean b) two independent means c) comparing means of dependent samples d) two independent proportions 6. What should our hypotheses be to test if your new method is better than the old method?

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 04/25/2010 for the course STA 2023 taught by Professor Ripol during the Spring '08 term at University of Florida.

### Page1 / 22

questions 3 - STA 2023 Practice Questions Final Exam What...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online