This preview shows pages 1–4. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Exam 2 Spring 2010 Name_________________________ Psych Stats Spring 2010 Brannick Exam 2 Instructions: Write your name and U number on the scantron. Answer any 40 of 45 questions on the exam by bubbling in the best of the four alternatives given. For those questions you wish to omit, bubble in “e.” If you answer all 45, I will choose the last 5 for you, so it is in your interest to pick 5 and bubble in “e”. You can take the printed exam with you. Give the scantron to your lab instructor (or proctor) when you are done. Handy formulas: N X X σ σ = N s s X X 2 = ; 1 ) ( 2 2 = ∑ N X X s X X X z σ μ = X obt s X t μ = X z X CI σ 05 . % 95 ± = X s t X CI 05 . % 95 ± = SD X X z = N X X ∑ = Tabled values of z, the unit normal. Z Between mean and z Beyond z Z Between mean and z Beyond z 0.00 0.0 50.00 0.90 31.5 18.41 0.10 3.98 46.02 1.00 34.13 15.87 0.20 7.93 42.07 1.10 36.43 13.57 0.30 11.79 38.21 1.20 38.49 11.51 0.40 15.54 34.46 1.30 40.32 09.68 0.50 19.15 30.85 1.40 41.92 08.08 0.60 22.57 27.43 1.50 43.32 06.68 0.70 25.80 24.20 1.60 44.52 05.48 0.80 28.81 21.19 1.65 45.00 05.00 1.70 45.54 04.46 1.96 97.50 02.50 Critical values of t , alpha = .05, twotails df t df t 1 12.706 6 2.447 2 4.303 7 2.365 3 3.182 8 2.306 4 2.776 9 2.262 5 2.571 10 2.228 1 Exam 2 Spring 2010 Chapter 5 Standard Error of the Mean 1.The sampling distribution is a distribution of what? a. A statistic over all possible samples b. All possible rolls of dice c. Raw scores drawn from a population d. Rejection regions 2. Suppose 50 people are repeatedly sampled from a population in which the standard deviation is 20. What would the standard error be? a. .4 b. 2.5 c. 20/sqrt(50) d. 50/sqrt(20) 3.Suppose a population mean is 10 and the standard error is .5 based on samples of N=500. What percentage of means in the sampling distribution should fall above 10 ? a. Cannot be determined b. 25 c. 50 d. 69.15 4.One of the main uses of statistics is to estimate ______. a. parameters b. populations c. qualities d. samples 5.What is the meaning of bias in the statistical sense? a. The degree to which the sampling distribution is skewed b. Whether the mean of the sampling distribution equals the parameter c. Whether the standard deviation of the sampling distribution equals zero d. Whether the standard deviation of the sampling distribution equals the parameter 6.Suppose the population value of the mean is 200, the population standard deviation is 10. Further suppose that we have sampled 25 people and found a sample mean of 210. What is the z score for our sample mean? a.5 b.1 c. 1 d. 5 2 Exam 2 Spring 2010 7.Suppose a standard deviation for raw scores is 14 and the sample size is 49. What is the standard error?...
View
Full
Document
This note was uploaded on 05/21/2011 for the course PSY 3204 taught by Professor Brannick during the Spring '10 term at University of South Florida  Tampa.
 Spring '10
 Brannick

Click to edit the document details