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Study Resources (Statistics)

    43.When the variation associated with blocks is removed from the data, SSE increases.     44.SSE in the independent samples design is equal to the sum of SSB and SSE in the randomized block design.     45.In the randomized block design for ANOVA, where k is the number of treatments and b is the number.
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  6.{Sub Sandwich Customers Narrative} Do these data provide enough evidence at the 5% significance level to infer that there are differences in ages among the customers of the three restaurants?     GMAT Scores   A recent college graduate is in the process of deciding which one of three graduate schools he should apply to..
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    93.{Migraine Treatments Narrative} Test at the 5% significance level to determine if differences exist among the levels of factor A.     94.{Migraine Treatments Narrative} Test at the 5% significance level to determine if differences exist among the levels of factor B.     Keyboard Configuration and Size   The data shown below were taken from a 2.
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  MULTIPLE CHOICE   1.The adjusted coefficient of determination is adjusted for the: a.number of independent variables and the sample size. b.number of dependent variables and the sample size. c.coefficient of correlation and the significance level. d.number of regression parameters including the y-intercept.       2.In a multiple regression analysis, if the model provides a poor fit, this indicates that: a.the.
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    33.{LSAT Scores Narrative} Use Fisher's LSD method with ? = 0.05 to determine which school's means differ.     34.{LSAT Scores Narrative} Use Tukey's method with ? = 0.05 to determine which population means differ.     35.The average cost of remodeling one room in a house was compared for four different remodeling companies. A random.
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    109.If you want to describe a population with more than two categories, which test(s) can you use?     110.If you want to compare two populations that each have two categories, which test(s) can you use?     111.If you want to compare two populations that each have more than two categories, which test(s) can you.
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    114.A councilwoman regularly polls her constituency to gauge her level of support among voters. This month, 652 out of 1158 voters support her. Five months ago, 412 out of 982 voters supported her. With a 5% significance level, can she infer that support has increased by at least 10 percentage.
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    11.A left-tailed area in the chi-squared distribution equals .90. For 10 degrees of freedom the table value equals 15.9871.     12.For a chi-squared distributed random variable with 12 degrees of freedom and a level of significance of .05, the test statistics is 25.168. The chi-squared value from the table is 21.0261. These.
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  MULTIPLE CHOICE   1.To determine the critical values in the chi-squared distribution table, you need to know the: a.sample size.c.probability of Type II error. b.degrees of freedomd.All of these choices are true.       2.Suppose the value of your chi-squared test statistic in a goodness-of-fit test is equal to 0. What do you conclude? a.Reject H0. Conclude that.
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  SHORT ANSWER   1.Consider the following statistics of a multiple regression model: Total variation in y = 1000, SSE = 300, n = 50, and k = 4.   a.Determine the standard error of estimate. b.Determine the coefficient of determination. c.Determine the F-statistic.       2.Consider the following statistics of a multiple regression model: n = 25, k.
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  SHORT ANSWER   TV News Viewing Habits   A statistician employed by a television rating service wanted to determine if there were differences in television viewing habits among three different cities in New York. She took a random sample of five adults in each of the cities and asked each to report the number.
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TRUE/FALSE   1.The F-test used in one-way ANOVA is an extension of the t-test of ?1 ? ?2.     2.We use the analysis of variance (ANOVA) technique to compare two or more population means.     3.The F-test in ANOVA tests whether or not the population variances are equal.     4.The sum of squares for treatments, SST, achieves its.
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  13.The Bonferroni adjustment to Fisher's Least Significant Difference (LSD) multiple comparison method is made by dividing the specified experimentwise Type I error rate by the number of pairs of population means.     14.The Bonferroni adjustment decreases the experimentwise Type I error rate, but it increases the probability of a Type II error.     15.Multiple.
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  COMPLETION   1.The ANOVA procedure tests to determine whether differences exist between two or more population ____________________.     2.The null hypothesis of ANOVA is that all the population means are ____________________.     3.The alternative hypothesis of ANOVA is that ____________________ population means are different.     4.In ANOVA the populations are classified according to one or more criterion, called.
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  COMPLETION   1.A(n) ____________________ experiment is like a binomial experiment except it contains two or more categories.     2.When k = 2 the ____________________ experiment is identical to the ____________________ experiment.     3.The chi-squared goodness-of-fit test compares the ____________________ frequencies in the table to the ____________________ frequencies based on the null hypothesis.     4.If the expected frequencies and.
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    63.{Food Irradiation Narrative} Set up the ANOVA Table. Use ? = 0.01 to determine the critical values.     64.{Food Irradiation Narrative} Can the company infer at the 1% significance level that differences in the bacteria count exist among the four irradiation methods?     Acid Reflux   A partial ANOVA table in a randomized block design is.
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  16.{Student Absenteeism Narrative} Review the previous results. What is the effect of decreasing the sample size?     Sales Volumes   A telemarketer makes five calls per day. A sample of 200 days gives the frequencies of sales volumes listed below:   Number of SalesObserved Frequency (days) 010 138 269 363 418 5  2   Assume the population is binomial distribution with a probability of.
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TRUE/FALSE   1.A chi-squared distribution is symmetric.     2.A chi-squared test is used to describe a population of nominal data.     3.The total of the observed frequencies in a multinomial experiment must equal nk where n is the number of trials and k is the number of categories.     4.In conducting a chi-squared goodness-of-fit test, an essential condition.
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  COMPLETION   1.A multiple regression model has the form . The coefficient b1 is interpreted as the change in the average value of y per unit change in ________ holding ________ constant.     2.Multiple regression has four requirements for the error variable. One is that the probability distribution of the error variable is ____________________.     3.The.
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  MULTIPLE CHOICE   1.The test statistic of the single-factor ANOVA equals: a.sum of squares for treatments / sum of squares for error. b.sum of squares for error / sum of squares for treatments. c.mean square for treatments / mean square for error. d.mean square for error / mean square for treatments.       2.In a single-factor analysis of variance,.
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    104.In constructing a confidence interval estimate for the difference between two population proportions, we ____________________ (always/sometimes/never) pool the population proportions.     105.The variance of the difference between two sample proportions equals the ____________________ of their population proportion variances.     106.The expected value of the difference between two sample proportions is the ____________________ of/between their.
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    99.There are two critical factors in identifying the technique used when the data are nominal. The first is the problem objective. The second is the number of ____________________ that nominal variable can assume.     100.If you want to describe a population with two categories, you can use a(n) ____________________ test of p.
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  11.A Deli proposes to serve 4 main Sandwiches. For planning purposes, the manager expects that the proportions of each that will be selected by her customers will be:   SelectionProportion Turkey.50 Roast Beef.20 Pastrami.10 Tuna.20   Of a random sample of 100 customers, 44 selected chicken, 24 selected roast beef, 13 selected Pastrami, and 10 selected tuna. Should.
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    69.{Seat Belts Narrative} At 5% level of significance, what is the critical value of the test statistic?     70.{Seat Belts Narrative} At 5% level of significance, what is the proper conclusion?     71.If we want to test for differences between two populations of nominal data with exactly two categories, we can employ either the.
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    11.A multiple regression model involves 10 independent variables and 30 observations. If we want to test at the 5% significance level whether one of the coefficients is = 0 (vs. ? 0) the critical value will be: a.2.228c.1.729 b.2.093d.1.697       12.A multiple regression model has the form . As x3 increases by one unit,.
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    94.The expected value of the difference between two sample proportions is the difference between their corresponding population proportions.     95.The variance of the difference in sample proportions equals the difference of their population variances.     96.For testing the difference between two population proportions, the pooled proportion estimate should be used to compute the value.
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    21.Consider the following partial ANOVA table:   Source of VariationSSdfMSF Treatments  75*25       6.67 Error  60*3.75 Total13519   The numerator and denominator degrees of freedom for the F-test (identified by asterisks) are a.4 and 15c.15 and 4 b.3 and 16d.16 and 3       22.Consider the following ANOVA table:   Source of VariationSSdfMSF Treatments  4  22.00.80 Error30122.5 Total3414   The number of treatments is a.13c.3 b.5d.12       23.In one-way analysis of variance, within-treatments variation.
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    39.The number of degrees of freedom for a contingency table with r rows and c columns is: a.r + c b.rc c.(r ? 1)(c ? 1) d.None of these choices.       40.If you reject H0 in a test of a contingency table, you conclude that based on your data: a.The two nominal variables are independent. b.The two nominal.
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    11.The F-statistic in a one-way ANOVA represents the variation within the treatments divided by the variation between the treatments.     12.The distribution of the test statistic for analysis of variance is the F-distribution.     13.The sum of squares for treatments (SST) is the variation attributed to the differences between the treatment means, while the.
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    84.{Antioxidants Narrative} Develop the 95% confidence interval estimate of the ratio of the two population variances.     85.{Antioxidants Narrative} Explain how to use the 95% confidence interval for testing the equality of the two population variances at the 5% level.     86.The pooled proportion estimate is used when the null hypothesis states that the.
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    83.A complete 3 ? 2 factorial experiment is called balanced if: a.data is collected at all three levels of factor A. b.data is collected at both levels of factor B. c.the number of replicates is the same for each of the 6 treatments. d.None of these choices.       84.Number of observation for particular combination of treatments.
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    53.The F-test of a randomized block design of the analysis of variance has the same requirements as the independent samples design; that is, the random variable must be ____________________ distributed and the population ____________________ must be equal.     54.SSE in the independent samples design is equal to the sum of SS____________________ and.
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    89.If we want to conduct a two-tail test of a population proportion, we can employ: a.z-test of a population proportion. b.the chi-squared test of a binomial experiment since z2 = ?2. c.the chi-squared test of a contingency table. d.Both a and b       90.Which statistical technique is appropriate when we describe a single population of qualitative.
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    74.{Fitness Program Narrative} Can the statistician conclude at the 5% significance level that the required condition is not satisfied?     75.{Fitness Program Narrative} Estimate with 95% confidence the ratio of the two population variances and interpret.     Profit Margin   An investor is considering two types of investment. She is quite satisfied that the expected profit.
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    11.The sampling distribution of the test statistic for a goodness-of-fit test with k categories is a: a.chi-squared distribution with k ? 1 degrees of freedom. b.normal distribution. c.Student t-distribution with k ? 1 degrees of freedom. d.None of these choices.       12.Which of the following conditions indicate that H0 should be rejected in a goodness-of-fit test? a.The.
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  19.In a test of a contingency table, rejecting the null hypothesis concludes the variables are not independent.     20.To produce expected values for a test of a contingency table, you multiply estimated joint probabilities for each cell by the total sample size, n.     21.To calculate the expected values in a test of a.
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    21.In a multiple regression model, the following statistics are given: SSE = 100, R2 = 0.995, k = 5, and n = 15. Then, the coefficient of determination adjusted for degrees of freedom is: a.0.992c.0.955 b.0.900d.0.855       22.In a multiple regression model, the error variable ? is assumed to have a mean of: a.?1.0c.1.0 b.0.0d.None of.
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    21.When an explanatory variable is dropped from a multiple regression model, the coefficient of determination can increase.     22.When an explanatory variable is dropped from a multiple regression model, the adjusted coefficient of determination can increase.     23.From the coefficient of determination, we cannot detect the strength of the relationship between the dependent variable.
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    79.Mathematical statisticians have established that if we square the value of z, the test statistic for the test of one proportion p, we produce the ?2 statistic. That is, z2 = ?2.     80.To describe a population with more than two categories you can only use a chi-squared goodness-of-fit test.     81.In testing the.
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    23.When is the Tukey multiple comparison method used? a.To test for normality. b.To test for differences in pairwise means. c.To test for equality of a group of population means. d.To test equal variances.       24.The techniques used to detect which population means differ are called multiple ____________________ methods.     25.Multiple comparison methods are used after it is found.
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    119.The number of degrees of freedom in testing for normality is the: a.number of intervals used to test the hypothesis minus one. b.number of parameters estimated minus one. c.number of intervals used to test the hypothesis minus one minus the number of parameters estimated. d.None of these choices.       120.The number of degrees of freedom in.
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    11.In a completely randomized design for ANOVA, the numerator and denominator degrees of freedom are 4 and 25, respectively. The total number of observations must equal: a.24c.29 b.25d.30       12.The number of degrees of freedom for the denominator in one-way ANOVA test involving 4 population means with 15 observations sampled from each population is: a.60c.56 b.19d.45       13.The.
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TRUE/FALSE   1.In multiple regression analysis, the adjusted coefficient of determination is adjusted for the number of independent variables and the sample size.     2.Most statistical software print a second R2 statistic, called the coefficient of determination adjusted for degrees of freedom, which has been adjusted to take into account the sample size and.
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    49.The alternative hypothesis in a chi-squared test of a contingency table is that the two nominal variables are ____________________.     50.You find the expected value for each cell in a chi-squared test for a contingency table by multiplying the ____________________ total by the ____________________ total and dividing by the sample size, n.     51.The.
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