chapter 17
Question 11 pts What happens to the critical value for a chi-square test if the size of the sample is increased?
| The critical value also increases. |
| The critical value decreases. |
| The critical value depends on the number of categories, not the sample size. |
| The critical value is determined entirely by the alpha level. |
Flag this Question Question 21 pts Which of the following accurately describes the observed frequencies for a chi-square test?
| They are always whole numbers. |
| They can contain fractions or decimal values. |
| They can contain both positive and negative values. |
| They can contain fractions and negative numbers. |
Flag this Question Question 31 pts A researcher obtains a negative value for chi-square statistic. What can you conclude because the value is negative?
| The observed frequencies are consistently larger than the expected frequencies. |
| The expected frequencies are consistently larger than the observed frequencies. |
| There are large differences between the observed and expected frequencies. |
| The researcher made a mistake; the value of chi-square cannot be negative. |
Flag this Question Question 41 pts A chi-square test for goodness of fit has df = 2. How many categories were used to classify the individuals in the sample?
| This cannot be determined without additional information. |
Flag this Question Question 51 pts Which of the following accurately describes the chi-square test for goodness of fit?
| It is similar to a single-sample t test because it uses one sample to test a hypothesis about one population. |
| It is similar to a correlation because it uses one sample to evaluate the relationship between two variables. |
| It is similar to an independent-measures t test because it uses separate samples to evaluate the difference between separate populations. |
| It is similar to both a correlation and an independent-measures t test because it can be used to evaluate a relationship between variables or a difference between populations. |
Flag this Question Question 61 pts For a chi-square test, the observed frequencies are obtained from the sample.
Flag this Question Question 71 pts A chi-square test for independence has df = 3. What is the total number of categories (cells in the matrix) that were used to classify individuals in the sample?
Flag this Question Question 81 pts For a fixed level of significance, the critical value for chi-square increases as the size of the sample increases.
Flag this Question Question 91 pts The chi-square test for independence uses the same formula as the chi-square statistic for the goodness-of-fit test.
Flag this Question Question 101 pts If other factors are held constant, increasing the sample size for a chi-square test for independence will increase the likelihood of rejecting the null hypothesis.
Chapter 7
Question 11 ptsSkip to question text. A sample of n = 16 scores is selected from a population with m = 80 with s = 20. On average, how much error would be expected between the sample mean and the population mean?
Flag this Question Question 21 pts For a population with µ = 80 and ó = 20, the distribution of sample means based on n = 16 will have an expected value of ____ and a standard error of ____.
Flag this Question Question 31 pts A random sample of n = 4 scores is obtained from a normal population with µ = 20 and s = 4. What is the probability that the sample mean will be greater than M = 22?
Flag this Question Question 41 pts What symbol is used to identify the standard error of M?
Flag this Question Question 51 ptsSkip to question text. A sample of n = 4 scores is obtained from a population with m = 70 and s = 8. If the sample mean corresponds to a z-score of 2.00, then what is the value of the sample mean?
Flag this Question Question 61 pts If a sample of n = 4 scores is obtained from a population with m = 70 and s = 12, then what is the z-score corresponding to a sample mean of M = 76?
Flag this Question Question 71 pts A sample of n = 9 scores is obtained from a population with m = 70 and s = 18. If the sample mean is M = 76, then what is the z-score for the sample mean?
Flag this Question Question 81 pts If random samples, each with n = 36 scores, are selected from a normal population with µ = 80 and s = 18, how much difference, on average, should there be between a sample mean and the population mean?
Flag this Question Question 91 pts If samples are selected from a normal population, the distribution of sample means will also be normal.
Flag this Question Question 101 pts As the sample size increases, the standard error also increases.
chapter 6
Question 11 pts A normal distribution has a mean of µ = 40 with ó = 10. What proportion of the scores in this distribution are greater than X = 55?
Flag this Question Question 21 pts A vertical line is drawn through a normal distribution at z = 0.50, and separates the distribution into two sections. What proportion of the distribution is in the larger section?
Flag this Question Question 31 pts A normal distribution has a mean of µ = 70 with s = 12. If one score is randomly selected from this distribution, what is the probability that the score will be greater than X = 58?
Flag this Question Question 41 pts A jar contains 10 red marbles and 30 blue marbles. What is the probability of randomly selecting a red marble from the jar?
Flag this Question Question 51 pts What proportion of a normal distribution is located in the tail beyond z = 2.00?
Flag this Question Question 61 pts What is the probability of randomly selecting a z-score less than z = 1.25 from a normal distribution.
Flag this Question Question 71 pts When the z-score value in a normal distribution is negative, the body is on the right-hand side of the distribution.
Flag this Question Question 81 pts A normal distribution has a mean of µ = 80 with s = 20. What score separates the highest 40% of the distribution from the rest of the scores?
Flag this Question Question 91 pts All probabilities can be expressed as decimal values ranging from 0 to 1.00.
Flag this Question Question 101 pts For a binomial distribution, the probability of obtaining a score of X = 19 or greater is computed as p(X > 18.5).
chapter 5
Question 11 pts A sample of n = 9 scores has a variance of s2 = 18. If the scores were a population, what value would be obtained for the population variance?
Flag this Question Question 21 ptsSkip to question text. For an exam with a mean of M = 74 and a standard deviation of s = 8, Mary has a score of X = 80, Bob’s score corresponds to z = +1.50, and Sue’s score is located above the mean by 10 points. If the students are placed in order from smallest score to largest score, what is the correct order?
Flag this Question Question 31 pts In a sample with M = 40 and s = 8, what is the z-score corresponding to X = 38?
Flag this Question Question 41 pts In a population of scores, X = 83 corresponds to z = –0.50 and X = 93 corresponds to z = +2.00. What are the values for the population mean and standard deviation?
Flag this Question Question 51 pts A population of scores has µ = 80. In this population, a score of X = 86 corresponds to z = +2.00. What is the population standard deviation?
Flag this Question Question 61 pts For a population with µ = 40 and s = 8, what is the X value corresponding to z = 1.50?
Flag this Question Question 71 ptsSkip to question text. Using z-scores, a population with µ = 37 and s = 6 is standardized so that the new mean is µ = 50 and s = 10. After the standardization, one individual has a score of X = 55. What was this individual’s score in the original distribution?
| It cannot be determined with the information given. |
Flag this Question Question 81 pts For a population with µ = 100 and s = 20, what is the X value corresponding to z = –0.75?
Flag this Question Question 91 ptsSkip to question text. A distribution with µ = 35 and s = 8 is being standardized so that the new mean and standard deviation will be µ = 50 and s = 10. In the new, standardized distribution your score is X = 45. What was your score in the original distribution?
Flag this Question Question 101 ptsSkip to question text. If an entire population with m = 60 and s = 8 is transformed into z-scores, then the distribution of z-scores will have a mean of ____ and a standard deviation of ____.
chapter 4
Question 11 pts A set of 10 scores has SS = 90. If the scores are a sample, the sample variance is ____ and if the scores are a population, the population variance is ____.
Flag this Question Question 21 pts What is the value of SS (sum of squared deviations) for the following population?
Population: 1, 1, 1, 5
Flag this Question Question 31 pts A population of N = 100 scores has µ = 30 and s = 4. What is the population variance?
Flag this Question Question 41 pts Which of the following symbols identifies the population standard deviation?
Flag this Question Question 51 pts A population has µ = 50 and s = 5. If 10 points are added to every score in the population, then what are the new values for the mean and standard deviation?
Flag this Question Question 61 pts A sample of n = 9 scores has a variance of s2 = 18. If the scores were a population, what value would be obtained for the population variance?
Flag this Question Question 71 pts A population of scores has µ = 50 and s = 5. If every score in the population is multiplied by 3, then what are the new values for the mean and standard deviation?
Flag this Question Question 81 pts On an exam with a mean of m = 70, you have a score of X = 75. Which of the following values for the standard deviation would give you the highest position within the class?
| It cannot be determined from the information given. |
Flag this Question Question 91 pts If the population variance is 4, then the standard deviation will be s = 16.
Flag this Question Question 101 pts For a population with µ = 70 and s = 5, about 95% of the individuals will have scores between X = 65 and X = 75.
chapter 3
Question 11 pts A population of N = 6 scores has SX = 30. What is the population mean?
Flag this Question Question 21 pts A population has a mean of µ = 30. If 3 points are added to each score, what is the mean for the new distribution?
| It cannot be determined from the information given. |
Flag this Question Question 31 pts For a negatively skewed distribution with a mean of M = 20, what is the most probable value for the median?
| It cannot be determined from the information given. |
Flag this Question Question 41 pts What is the mean for the following sample of scores?
Scores: 1, 4, 5, 10
Flag this Question Question 51 pts A population of scores has a mean of µ = 26, a median of 23, and a mode of 22. What is the most likely shape for the population distribution?
| It cannot be determined from the information given. |
Flag this Question Question 61 pts A sample with a mean of M = 20 has SX = 120. There are n = 6 scores in the sample.
Flag this Question Question 71 pts For a set of scores measured on an ordinal scale, the median is the preferred measure of central tendency.
Flag this Question Question 81 pts A sample has n = 5 scores: 2, 4, 5, 8, and 11. The median for the sample is 6.5.
Flag this Question Question 91 pts A distribution of scores has a mean of 50, a median of 53, and a mode of 56. Based on this information it appears that the distribution is negatively skewed.
Flag this Question Question 101 pts The mean is considered to be the “balance point” for a distribution because exactly half of the scores are located above the mean and exactly half are below the mean.
Question 11 pts On a multiple-choice exam for which each question has four possible answers, the probability of guessing the correct answer is p = 1/4. What is the mean of the binomial distribution for the number of correct guesses for a series of 100 questions?
Flag this QuestionQuestion 21 pts Which of the following is true for any binomial test?
Flag this QuestionQuestion 31 pts For a binomial distribution with p = 0.10 and n = 100, what is the range of possible values for X?
Flag this QuestionQuestion 41 ptsSkip to question text. A researcher is testing a null hypothesis stating that for the general population there is no preference between the two leading brands of cola. In a sample of n = 100 people, 35 preferred brand A and 65 preferred brand B. Assuming that the researcher uses a two-tailed test, what is the appropriate statistical decision?
| Reject the null hypothesis with a = .05 but not with a = .01. |
| Reject the null hypothesis with either a = .05 or a = .01. |
| Fail to reject the null hypothesis with either a = .05 or a = .01. |
| No decision is possible without additional information. |
Flag this QuestionQuestion 51 pts For a binomial distribution with p = 1/2 and n = 30, the value of X ranges from 1 to 30.
Flag this QuestionQuestion 61 pts For a binomial distribution based on n = 100, the standard deviation would be larger for p = 0.90 than for p = 0.80.
Flag this QuestionQuestion 71 pts For the normal approximation to the binomial distribution with p = 1/2 and n = 100, what is the z-score corresponding to X = 60?
Flag this QuestionQuestion 81 pts Which of the following tests is often used for the same kind of research study for which the sign test is appropriate?
| An independent-measures t test |
| A repeated-measures t test |
| A chi-square test for goodness of fit |
Flag this QuestionQuestion 91 pts The binomial distribution with p = .10 has a mean of m = 10. For this distribution, there are n = 100 scores in the sample.
Flag this QuestionQuestion 101 pts If other factors are held constant, both the mean and standard deviation for the binomial distribution will both increase as the sample size increases.
Chapter 16
Question 11pts If there is a positive correlation between X and Y then the regression equation, Y = bX + a will have ____.
Flag this QuestionQuestion 21pts For a linear regression equation calculated for a sample of n = 20 pairs of X and Y values, what would be the df value for the standard error of estimate?
Flag this QuestionQuestion 31pts One use of regression equation is to increase the accuracy of predicting Y scores. How much of the variability in the Y scores is predictable from the regression equation?
Flag this QuestionQuestion 41pts The multiple regression with two predictor variables is computed for a sample of n = 25 participants. What is the value for degrees of freedom for the predicted portion of the Y-score variance, MSregression?
Flag this QuestionQuestion 51ptsSkip to question text. A multiple regression equation is computed for a sample of n = 20 sets of X1, X2, and Y scores. If the significance of the regression equation is evaluated using an F-ratio, then the ratio would have degrees of freedom equal to ____.
Flag this QuestionQuestion 61pts For a linear regression equation computed for a sample of n = 30, the unpredicted portion of the Y-score variance (MSresidual) has df = 28.
Flag this QuestionQuestion 71pts For either linear regression or multiple regression, the standard error of estimate can be computed as ____.
| the square root of MSresidual |
| the square root of MSregression |
Flag this QuestionQuestion 81pts In a multiple regression equation with two predictor variables, if b1is larger than b2, then X1is a better predictor of the Y-score variance than is X2.
Flag this QuestionQuestion 91pts The F-ratio evaluating the significance of a linear regression equation based on n = 10 pairs of X and Y scores has df = 1, 8.
Flag this QuestionQuestion 101pts If the Pearson correlation between X and Y is r = 0.60, then the regression equation predicts 36% of the variance in the Y scores.
Chapter 19
Given a series of numbers: 8,7,6,4,4,3 compute the Mean, Median and Mode
