If the professionals and the students do not differ in the distributions of their responses, which of the following is equal to the expected number of students who classify the crown shapes as medium?
A) 39
B) ((39)(87))/91
C) ((87)(91))/200
D) ((87)(109))/200
E) ((97)(91))/200
Questions and Answers
A statistician is conducting a chi-square goodness-of-fit test and is limited by the cost, per individual, to conduct the study. The statistician selects a sample of size 39, which is the smallest sample possible that will meet the condition for large expected counts. Which of the following could not be the null hypothesis for the study? A) H0: p1=0.20, p2=0.20, p3=0.20, p4=0.20, p5=0.20 B) H0: p1=0.15, p2=0.35, p3=0.22, p4=0.15, p5=0.13 C) H0: p1=0.24, p2=0.23, p3=0.21, p4=0.18, p5=0.14 D) H0: p1=0.34, p2=0.21, p3=0.14, p4=0.15, p5=0.16 E) H0: p1=0.43, p2=0.23, p3=0.17, p4=0.09, p5=0.08
A statistician is conducting a chi-square goodness-of-fit test and is limited by the cost, per individual, to conduct the study. The statistician selects a sample of size 39, which is the smallest sample possible that will meet the condition for large expected counts. Which of the following could not be the null hypothesis for the study?
A) H0: p1=0.20, p2=0.20, p3=0.20, p4=0.20, p5=0.20
B) H0: p1=0.15, p2=0.35, p3=0.22, p4=0.15, p5=0.13
C) H0: p1=0.24, p2=0.23, p3=0.21, p4=0.18, p5=0.14
D) H0: p1=0.34, p2=0.21, p3=0.14, p4=0.15, p5=0.16
E) H0: p1=0.43, p2=0.23, p3=0.17, p4=0.09, p5=0.08
l. H0: p1=p2=p3, where p1 is the proportion of the sample of sophomores that responded yes, p2 is the proportion of the sample of juniors that responded yes, and p3 is the proportion of the sample of seniors that responded yes. ll. H0: There is an association between grade level and whether or not a student regularly recycles plastic bottles. lll. H0: There is no difference in the distribution of regular recyclers across the three grade levels. A) II only B) III only C) I and II only D) I and III only E) I, II, and III
l. H0: p1=p2=p3, where p1 is the proportion of the sample of sophomores that responded yes, p2 is the proportion of the sample of juniors that responded yes, and p3 is the proportion of the sample of seniors that responded yes. ll. H0: There is an association between grade level and whether or not a student regularly recycles plastic bottles. lll. H0: There is no difference in the distribution of regular recyclers across the three grade levels.
A) II only
B) III only
C) I and II only
D) I and III only
E) I, II, and III
The corresponding p-value of 0.03 means that the probability of observing a test statistic of χ2=12.4 is 0.03, assuming the null hypothesis is true. Which of the following is a valid criticism of this interpretation of the p-value? A) The null hypothesis can never be assumed to be true. B) The null hypothesis is not stated. C) The p-value is not the probability of observing 12.4 exactly. D) The significance level is not stated. E) The degrees of freedom are not stated.
The corresponding p-value of 0.03 means that the probability of observing a test statistic of χ2=12.4 is 0.03, assuming the null hypothesis is true. Which of the following is a valid criticism of this interpretation of the p-value?
A) The null hypothesis can never be assumed to be true.
B) The null hypothesis is not stated.
C) The p-value is not the probability of observing 12.4 exactly.
D) The significance level is not stated.
E) The degrees of freedom are not stated.
If children from these countries exhibit top rounding in the same proportions, what is the expected count for Malay children who show top rounding? A) 938 B) 951 C) 9 D) ((38)(51))/153 E) ((38)(9))/153
If children from these countries exhibit top rounding in the same proportions, what is the expected count for Malay children who show top rounding?
A) 938
B) 951
C) 9
D) ((38)(51))/153
E) ((38)(9))/153
A quality control specialist tests samples of the seed being packaged and uses a chi-square goodness-of-fit test to see whether the proportions in the samples match what is claimed by the company. Which of the following best describes the null hypothesis and the alternative hypothesis for the test? A) H0: p=0.20 Ha: p≠0.20 B) H0: pF=0.20, pB=0.20, pBG=0.20, pI=0.20, pNG=0.20 Ha: At least one of the proportions is different. C) H0: pF=0.55, pB=0.22, pBG=0.10, pI=0.07, pNG=0.06 Ha: At least one of the proportions is different. D) H0: All proportions are equally likely. Ha: All of the proportions are different. E) H0: There is no association between the grass-seed types. Ha: There is an association between the grass-seed types.
A quality control specialist tests samples of the seed being packaged and uses a chi-square goodness-of-fit test to see whether the proportions in the samples match what is claimed by the company. Which of the following best describes the null hypothesis and the alternative hypothesis for the test?
A) H0: p=0.20 Ha: p≠0.20
B) H0: pF=0.20, pB=0.20, pBG=0.20, pI=0.20, pNG=0.20 Ha: At least one of the proportions is different.
C) H0: pF=0.55, pB=0.22, pBG=0.10, pI=0.07, pNG=0.06 Ha: At least one of the proportions is different.
D) H0: All proportions are equally likely. Ha: All of the proportions are different.
E) H0: There is no association between the grass-seed types. Ha: There is an association between the grass-seed types.
Jimmy believes that the shuffle feature on his music player is malfunctioning by not playing songs that meet this distribution of music types. To test this, he listens to 100 songs randomly chosen when his player is in shuffle mode and records the number of songs in each category. Which inference procedure should he use to test whether or not the shuffle feature is working correctly? A) A one-sample z-test for a population proportion B) A two-sample z-test for a difference between population proportions C) A chi-square goodness-of-fit test D) A chi-square test for homogeneity E) A matched pairs t-test for a mean difference
Jimmy believes that the shuffle feature on his music player is malfunctioning by not playing songs that meet this distribution of music types. To test this, he listens to 100 songs randomly chosen when his player is in shuffle mode and records the number of songs in each category. Which inference procedure should he use to test whether or not the shuffle feature is working correctly?
A) A one-sample z-test for a population proportion
B) A two-sample z-test for a difference between population proportions
C) A chi-square goodness-of-fit test
D) A chi-square test for homogeneity
E) A matched pairs t-test for a mean difference
Ms. Harper knows that her students in a computing course can choose from one of three operating systems for the semester: Doors, Banana, or Duix. Ms. Harper wants to test the hypothesis that her students will select the operating systems in the same proportion as students in other computing courses at the university. She conducts a χ2 goodness-of-fit test and calculates χ2=3.79 with a corresponding p-value of 0.15. Which of the following is correct at a 5-percent level of significance? A) Reject the null hypothesis, since 3.79>2. B) Fail to reject the null hypothesis, since 3.79>2. C) Reject the null hypothesis, since 0.15>0.05. D) Fail to reject the null hypothesis, since 0.15>0.05. E) Reject the null hypothesis, since 0.15<3.790.
Ms. Harper knows that her students in a computing course can choose from one of three operating systems for the semester: Doors, Banana, or Duix. Ms. Harper wants to test the hypothesis that her students will select the operating systems in the same proportion as students in other computing courses at the university. She conducts a χ2 goodness-of-fit test and calculates χ2=3.79 with a corresponding p-value of 0.15. Which of the following is correct at a 5-percent level of significance?
A) Reject the null hypothesis, since 3.79>2.
B) Fail to reject the null hypothesis, since 3.79>2.
C) Reject the null hypothesis, since 0.15>0.05.
D) Fail to reject the null hypothesis, since 0.15>0.05.
E) Reject the null hypothesis, since 0.15<3.790.
A spinner made for a game of chance has 8 equally likely spaces. Alfonso records the result of a sample of 400 spins. Alfonso decides to calculate a chi-square test statistic for a goodness-of-fit test to see whether the spinner is fair. Which of the following is the appropriate null hypothesis? A) H0 =0.125,p2=0.125,p3=0.125,p4=0.125,p5=0.125,p6=0.125,p7=0.125,p8=0.12 B) H0:H0: At least one proportion is different. C) H0 =0.125 D) H0 ≠0.125,p2≠0.125,p3≠0.125,p4≠0.125,p5≠0.125,p6≠0.125,p7≠0.125,p8≠0.125 E) H0 =0.08,p2=0.08,p3=0.08,p4=0.08,p5=0.08,p6=0.08,p7=0.08,p8=0.08
A spinner made for a game of chance has 8 equally likely spaces. Alfonso records the result of a sample of 400 spins. Alfonso decides to calculate a chi-square test statistic for a goodness-of-fit test to see whether the spinner is fair. Which of the following is the appropriate null hypothesis?
A) H0
=0.125,p2=0.125,p3=0.125,p4=0.125,p5=0.125,p6=0.125,p7=0.125,p8=0.12
B) H0:H0: At least one proportion is different.
C) H0
=0.125
D) H0
≠0.125,p2≠0.125,p3≠0.125,p4≠0.125,p5≠0.125,p6≠0.125,p7≠0.125,p8≠0.125
E) H0
=0.08,p2=0.08,p3=0.08,p4=0.08,p5=0.08,p6=0.08,p7=0.08,p8=0.08
A certain type of legal proceeding has three possible outcomes: in favor of party A, in favor of party B, or not in favor of either party. The outcomes are expected to be 40 percent, 20 percent, and 40 percent, respectively. A random sample of 40 cases is selected from a certain judge to investigate whether the judge’s outcomes are consistent with the expected outcomes. A chi-square goodness-of-fit test is conducted, and the value of the chi-square test statistic is χ2=9.19 with a corresponding p-value of 0.01. Assuming the conditions for inference were met, which of the following is the correct interpretation of the p-value? A) There is a 1 percent chance that the company’s claim is correct. B) If the null hypothesis is true, there is a 1 percent chance that the company’s claim is correct. C) If the null hypothesis is true, there is a 1 percent chance of obtaining a chi-square value of 9.19. D) If the null hypothesis is true, there is a 1 percent chance of obtaining a chi-square value of at least 9.19. E) There is a 1 percent chance of obtaining a chi-square value of at least 9.19.
A certain type of legal proceeding has three possible outcomes: in favor of party A, in favor of party B, or not in favor of either party. The outcomes are expected to be 40 percent, 20 percent, and 40 percent, respectively. A random sample of 40 cases is selected from a certain judge to investigate whether the judge’s outcomes are consistent with the expected outcomes. A chi-square goodness-of-fit test is conducted, and the value of the chi-square test statistic is χ2=9.19 with a corresponding p-value of 0.01. Assuming the conditions for inference were met, which of the following is the correct interpretation of the p-value?
A) There is a 1 percent chance that the company’s claim is correct.
B) If the null hypothesis is true, there is a 1 percent chance that the company’s claim is correct.
C) If the null hypothesis is true, there is a 1 percent chance of obtaining a chi-square value of 9.19.
D) If the null hypothesis is true, there is a 1 percent chance of obtaining a chi-square value of at least 9.19.
E) There is a 1 percent chance of obtaining a chi-square value of at least 9.19.