QNT 561 Final Exam

QNT 561 Final Exam 1. A difference between calculating the sample mean & the population mean is A. Only in the symbols, we use instead of µ & n instead of N B. We divide the sum of the observations by n - 1 instead of n C. The observations are ranked & select the middle value for the population mean D. There are no differences 2. Which of the following measures of central location is affected most by extreme values? A. Median B. Mean C. Mode D. Geometric mean 3. Which level of measurement is required for the median? A. Nominal B. Ordinal C. Interval D. Ratio 4. In which of the following distributions is the probability of a success usually small? A. Binomial B. Poisson C. Hyper geometric D. All distribution 5. Which of the following is not a requirement of a probability distribution? A. Equally likely probability of a success B. Sum of the possible outcomes is 1.00 C. The outcomes are mutually exclusive D. The probability of each outcome is between 0 & 1 6. Which of the following is not a requirement of a binomial distribution? A. A constant probability of success B. Only two possible outcomes C. A fixed number of trails D. Equally likely outcomes 7. A sample A. Is a part of the population B. Has more than 30 observations C. Is usually identified as N D. All of the above 8. The difference between the sample mean & the population mean is called the A. Population mean. B. Population standard deviation C. Standard error of the mean D. Sampling error 9. Suppose a population consisted of 20 items. How many different sample of n = 3 are possible? A. 6840 B. 1140 C. 20 D. 120 10. A point estimate is A. Always an estimate of the population mean B. Always equal to the population value C. An estimate of the population parameter D. None of the above 11. We wish to develop a confidence interval for the population mean. The population follows the normal distribution, the standard deviation of the population is 3, & we have a sample of 10 observations. We decide to use the 90 percent level of confidence. The appropriate value of to represent the level of confidence is A. z =1.65 B. z = 1.96 C. t = 1.833 D. t = 1.812 12. A confidence interval A. Always includes the population parameter B. Decreases in width as the sample size is increased C. Cannot include a value of 0 D. None of the above 13. The Special Rule of Addition is used to combine A. Independent events B. Mutually exclusive events C. Events that total more than one D. Events based on subjective probabilities 14. We use the General Rule of Multiplication to combine A. Events that are not independent B. Mutually exclusive events C. Events that total more than 1.00 D. Events based on subjective probabilities 15. An experiment is a A. Collection of events B. Collection of outcomes C. Always greater than 1 D. The act of taking a measurement or the observation of some activity 16. Which of the following statements is true regarding a sample? A. It is a part of population B. It must contain at least five observations C. It refers to descriptive statistics D. All of the above are correct 17. Which of the following statements is true regarding a population? A. It must be a large number of values B. It must refer to people C. It is a collection individuals, objects, or measurements D. None of the above 18. A nominal scale variable is A. Usually the result of counting something B. Has a meaningful zero point C. May assume negative values D. Cannot have more than two categories 19. In a two-sample test of means for independent samples, the equal sign always appears in A. The null hypothesis B. The alternate hypothesis C. The upper tail of the test statistic D. None of the above 20. The alternate hypothesis A. Is accepted if the null hypothesis is rejected B. Will always contain the equal sign C. Tells the value of the sample mean D. None of the above 21. Which of the following is a requirement for a two-sample test of proportions? A. The population standard deviations are equal B. Both populations are positively skewed C. Both samples are at least 30 D. n & n(1-) are both greater than 5 22. In a contingency table A. The number of rows must be the same as the number of columns B. A variable is classified according to two criteria C. There must be at least 10 observations in each cell D. All of the above 23. To conduct a nonparametric test the A. Population must follow the normal distribution B. The standard deviation must be known C. It is not necessary to make any assumption about the shape of the population D. The data must be at least interval scale 24. In a goodness-of-fit test where the sample size is 200, there are 5 categories, & the significance level is .05. The critical value of X2 is A. 9.488 B.11.070 C. 43.773 D. None of the above 25. A dummy variable or indicator variable A. May assume only a value of 0 or 1 B. Is another term for the dependent variable C. Is found by (Y - Y') D. Is equal to Y' 26. The multiple standard error of estimate is A. Is based on the (Y - Y')2 B.Is negative when one of the net regression coefficients is 0 C. Is found by taking the square root of SSR/SS total D. All of the above 27. A correlation matrix A. Shows all simple coefficients of correlation B. Shows all possible net regression coefficients C. Shows the correlations that are positive D. Reports the multiple regression equation 28) The difference between a random variable & a probability distribution is: A. A random variable does not include the probability of an event. B. A random variable can only assume whole numbers. C. A probability distribution can only assume whole numbers. D. None of the above. 29) The mean & the variance are equal in A. The binomial distribution. B. All probability distributions. C. The Poisson distribution. D. The hypergeometric distribution. 30) Events are independent if A. The probability of their occurrence is greater than 1. B. By virtue of one event happening another cannot. C. We can count the possible outcomes. D. The probability of one event happening does not affect the probability of another event happening. 1) Which of the following is a correct statement about a probability? . It may assume negative values. . It cannot be reported to more than 1 decimal place. . It may range from 0 to 1. . It may be greater than 1. 32) The ratio scale of measurement . Cannot assume negative values. . Is usually based on counting. . Usually involves ranking. . Has a meaningful zero point. 33) In a two-sample test of means for independent samples, we use the z distribution when A. Both populations have at least 4,000 observations. . nB & n(1-B) are both greater than 5. C. The population standard deviations are equal. . Both population standard deviations are known 34) Which of the following is not a characteristic of the X2 . It is not negative. . It approaches a normal distribution as the degrees of freedom increase. . Its shape is based on the sample size. . It is positively skewed. 35) In a multiple regression equation . There is only one dependent variable. . The R2 term must be at least .50. . All the regression coefficient must be between -1.00 & 1.00. . None of these 1. A new type of screening for lung cancer , CT, has been developed. Medical researchers believe that CT scans are more sensitive than regular X-rays in pinpointing small tumors. A university is conducting a medical trial of 50,000 smokers nationwide to compare the effectiveness of CT scans with X-rays for detecting lung cancer… One goal of the study is to compare the mean ages when cancer is first detected by the two screening methods. a. The response variable of the study: Age. b. Experimental units of the study: Smokers. c. Factors in the study: Screening methods. d. Treatments in the study: CT scan or X-rays. 2. A study of Machiavellian traits in consultants was performed… The consultants were then classified as having dishonest, neutral, or honest Mach rating scores. The researcher investigated the impact of both Mach score & gender on the average income of a consultant. a. Experimental units: Consultants. b. Response variable: Income. c. The factors: Gender; Mach score classification. d. Levels of each factor: The levels for Mach score classification are dishonest, neutral, & honest. The levels for gender are male & female. e. Treatments: (dishonest,male) (dishonest, female) (neutral, male) (neutral,female) (honest,male) (honest,female). 3. Consider the dot plots A & B. Plot A: Sample 1: 6,7,8,8,9,10 Sample 2: 12,13,14,14,15,16 Plot B: Sample 1: 5,5,7,11,13,13 Sample 2: 10,12,12,16,16,18 Plot A: Source df SS MS F Treatment 1 108 108 54 Error 10 20 2 Total 11 128 Plot B: Source df SS MS F Treatment 1 75 75 6.25 Error 10 120 12 Total 11 195 4. The partially completed ANOVA table for a 3x4 factorial experiment with two replications is shown below: