Inferential statistics

 

QUESTION 1

1. In an ANOVA, what are the degrees of freedom for the following output: 
   
   
   ANOVA      Source of VariationSSdfMSFP-valueF critBetween Groups71.64921235.82462.5037160.1152793.68232Within Groups214.62861514.30857          Total286.277817    
   2, 152, 172.5017

5 points   

QUESTION 2

1. Males and females were compared for the mean number of smiles during a five-minute interview. The 30 males' mean was 3.62 and the 24 females' mean was 5.04. An α level of .05 was adopted and an F = 4.02 was obtained. What conclusion is appropriate?males smile more than femalesfemales smile more than malesthe null hypothesis should be retainednone of the choices are correct

5 points   

QUESTION 3

1. The one way ANOVA is not appropriate if the data come fromneither choice is correctboth choices are correctpopulations that do not have the same meanpaired-samples design;

5 points   

QUESTION 4

1. The null hypothesis in an ANOVA problem is thatone or more of the groups was drawn from a different population;none of the groups were drawn from the same population;any of the other alternatives, depending on how many levels of the independent variable there are.all the groups are drawn from the same population;

5 points   

QUESTION 5

1. When the F value in the F table is smaller than the F value calculated from the datareject the null hypothesis;none of the choices are correctretain the null hypothesis;reject or retain the null hypothesis, depending on how far apart the group means are;

5 points   

QUESTION 6

1. A researcher conducted a paired sample t-test to determine if advertisements were viewed more in the morning (before noon) or in the evening (after 5pm) for eight different universities.  The results were as follows: 
   
   
   MorningEvening MorningEveningMean3240.625Variance89.71428571504.5536Observations88Pearson Correlation0.343785438 Hypothesized Mean Difference0 df7 t Stat-1.152587077 P(T<=t) one-tail0.143458126 t Critical one-tail1.894578605 P(T<=t) two-tail0.286916252 t Critical two-tail2.364624252
   
   Is there a significant difference between morning and evening access to the university advertisements?  Yes, there was a significant difference between Morning (M= 32), and Evening (M=40.625), (t [7] = 1.15 p < .05).No, there was no difference between Morning (M= 32), and Evening (M=40.625), (t [7] = 1.15, p < .05).
   
   No, there was no difference between Morning (M= 32), and Evening (M=40.625), (t [7] = 1.15, p > .05).
   
   Yes, there was a significant difference between Morning (M= 32), and Evening (M=40.625), (t [7] = .28, p < .05).
   
   

5 points   

QUESTION 7

1. p < .01 means that the
   
   the results are significantneither choice is significant the null hypothesis should be rejectedboth choices are correct

5 points   

QUESTION 8

1. In an independent samples design, the Dog's mean was 54.0 and the Cat's mean was 53.9. Larger scores are better. A t value of 2.50 was calculated and an α level of .05 adopted. Which conclusion is appropriate with a 2-tailed test?If df = 5, Dogs are significantly better than CatsIf df = 9, Dogs are not significantly different from CatsIf df = 10, Dogs are significantly better than CatsIf df = 4, Cats are significantly better than Dogs

5 points   

QUESTION 9

1. p < .05 means that the difference between sample meansnone of the choices are correctthe results should be declared "not significant";both choices are correctshould be attributed to chance rather than to the independent variable

5 points   

QUESTION 10

1. With an acknowledgment to Sesame Street, "Which of these things is not like the others, which of these things doesn't belong?"matched pairsnatural pairsrepeated measuresindependent samples