Hypothesis Testing – Week 2 Quiz. with Answers, Exams of Statistical Physics

Download Hypothesis Testing – Week 2 Quiz. with Answers and more Exams Statistical Physics in PDF only on Docsity! Hypothesis Testing – Week 2 Quiz. with Answers 1) The question in the independent t-test is which of the following? Do the samples belong to populations with the same mean? 2) The z scores is a ratio of difference to variability (t). True. 3) In the t-test, the dependent variable is nominal scale. False. 4) If you took a test, your standard score would indicate how many standard deviations you ended up away from the . Mean. 5) What is the symbol for data variability in the distribution of sample means? sM 6) What does statistically significant mean? The result is unlikely to be a chance outcome. 7) The standard error of the difference is a measure of pooled variance. True. 8) The table value z = .70 is .2580. What percent of the population occurs below that point? 75.80 % 9) The measure of within-group data variability in the independent t-test is . the estimated standard error of the difference 10) The central limit theorem maintains . distributions based on samples tend to be normal 1) How should a probability value of p = .1 should be interpreted? The event occurs about one time in every 10. 2) A type I decision error occurs in which of the following circumstances? Erroneously determining that a result is significant 3) A confidence interval for a z-test result establishes . the interval within which the mean of the alternate population is likely to occur 4) What is the similarity between the z test and the one-sample t-test? They both analyze differences between a sample and a population. 5) Turning raw scores into z scores does not make the data involved in the transformation normal 6) The central limit theorem maintains . distributions based on samples tend to be normal 7) Another name for the null hypothesis is . the hypothesis of no difference 8) The z-score transformation makes non-normal scores normal. False 9) What is the most common standard for statistical significance? Results in the most extreme 5% of possible outcomes 10) What is the critical value of t for a two-tailed t-test in which n = 10? 2.262 Question 1 0.5 / 0.5 pts In the independent t-test how many population parameter values are required? Correct! 0 1 2 3 Found in section 5.4, The Independent t-Test. Question 2 0.5 / 0.5 pts What is the meaning of “error” in the standard error of the mean? Correct! It refers to unexplained data variability. It refers to unexpected variability. It refers to how much error in estimation is expected. It refers to the degree to which an analysis will be inaccurate. Found in section 4.1, The Distribution of Sample Means. The standard deviation of the distribution The mean of the distribution An alternative value of z Correct! The raw score Found in section 3.5, Working Backward from z. Question 10 0.5 / 0.5 pts Which is true of one-tailed and two-tailed t-tests? They use the same critical values from the table. They require data of different scales for the independent and dependent variables. They have different standards for statistical significance in the test. Correct! They make different assumptions about how the sample will differ. Found in section 5.2, The One-Sample t-Test. What makes it possible to interpret negative values of z from a table that includes only positive values? (Points : 1) XXThe fact that normal distributions are symmetrical The fact that the z distribution has s = 1.0 The fact that there are no negative values of z The fact that normal distributions all have the same value of the mean Another name for the null hypothesis is . (Points : 1) the research hypothesis the test hypothesis XX xthe hypothesis of no difference the hypothesis of difference What advantage does the one-sample t offer over the z-test? (Points : 1) XX The one sample t requires no parameter standard error of the mean. The one sample t requires no parameter mean. The one sample t requires no sample mean. The one sample t doesn’t require interval scale data. What does statistically significant mean? (Points : 1) The result is important. XX The result is unlikely to be a chance outcome. The result is unlikely to be an error. The result is consistent with previous research. The distribution of sample means refers to . (Points : 1) an array of sample means an analysis of the means of samples XX a population based on sample means a group of sample means arranged by sample size The distribution upon which the z-test is based has a mean of 1.0. (Points : 1) True XX False Random selection refers to which of the following? (Points : 1) Selecting in order to accommodate each of the major subgroups Selecting every nth person so as to be representative Selecting the most convenient group XX Selecting so that everyone has an equal chance of inclusion What is the symbol for data variability in the distribution of sample means? (Points : 1) s XX sM mM m What is the similarity between the z test and the one-sample t-test? (Points : 1) They both analyze differences between sample means. XX They both analyze differences between a sample and a population. They both determine the strength of the relationship between variables. They both rely on ordinal scale data. If instead of z = (x – M)/s the formula is x = z(s) + M, what is the result? (Points : 1) XX The raw score An alternative value of z The mean of the distribution The standard deviation of the distribution Question 1 0.5 / 0.5 pts In the independent t-test how many population parameter values are required? Correct! 0 1 2 3 Found in section 5.4, The Independent t-Test. Question 2 0.5 / 0.5 pts What’s the impact on the size of the needed sample of changing from .01 The fact that normal distributions all have the same value of the mean The fact that there are no negative values of z The fact that the z distribution has s = 1.0 Correct! The fact that normal distributions are symmetrical Found in section 3.2, The Standard Normal Distribution. Question 6 0 / 0.5 pts The independent t-test is based on which distribution? The standard normal distribution The distribution of sample means Correct Answer The distribution of difference scores The distribution of mean scores Found in section 5.4, The Independent t-Test. Question 7 0.5 / 0.5 pts Consulting Table 3.1, what percentage of the distribution occurs below z = 1.0? 84.13% 50% 34.13% 15.87% Found in section 3.2, The Standard Normal Distribution. Question 8 0.5 / 0.5 pts The question in the independent t-test is which of the following? Is the sample significantly different from the population? Does one sample have a mean value greater than the other? Is the variability in one sample greater than in the other? Correct! Do the samples belong to populations with the same mean? Found in section 5.4, The Independent t-Test. Question 9 0.5 / 0.5 pts The distribution of sample means refers to . an array of sample means an analysis of the means of samples Correct! a population based on sample means a group of sample means arranged by sample size