The following scenario applies to questions 1-5: There are various sources of flickering lights in our environment; for instance, light from computerscreens and fluorescent bulbs.
The following scenario applies to questions 1-5:
There are various sources of flickering lights in our environment; for instance, light from computerscreens and fluorescent bulbs. Whether or not the human eye can detect the flicker depends on itsfrequency. A 1973 study ("The effect of iris color on critical flicker frequency," Journal of GeneralPsychology [1973], 91- 95) obtained data from a random sample of 19 subjects and recorded eye colorand Critical Flicker Frequency (CFF), a numerical measure of threshold sensitivity to flickering light. Dothe data suggest that threshold sensitivity to flickering light is related to eye color?
The following scenario applies to questions 1-5: There are various sources of flickering lights in our environment; for instance, light from computer screens and fluorescent bulbs. Whether or not the human eye can detect the flicker depends on its frequency. A 1973 study ("The effect of iris color on critical flicker frequency," Journal of General Psychology [1973], 91- 95) obtained data from a random sample of 19 subjects and recorded eye color and Critical Flicker Frequency (CFF), a numerical measure of threshold sensitivity to flickering light. Do the data suggest that threshold sensitivity to flickering light is related to eye color? Question 1 1 pts 1. What are the correct null and alternative hypotheses? (In this problem, UBI = mean threshold sensitivity for blue eyes, UG = mean threshold sensitivity for green eyes, and uBr = mean threshold sensitivity for brown eyes) o HO: HBI = HG = HBr VS. Ha: at least one mean is different . HO: HBI = HG = HBr VS. Ha: all of the means are different O HO : HBI = HG= MBr VS. Ha: MBI*MG * HBr HO: MBI = MG = MBr VS. Ha: HBI *HG = MBr Question 2 1 pts 2. Is the randomness condition met for this test? No, because a random sample was not taken. No, because there was not random allocation of treatments Yes, because each eye-color group was randomly assigned a treatment. Yes, because a random sample was taken. Question 3 1 pts 3. Is the normality condition met for this test? Below are boxplots of the data: CF Green2? I. ENC-ht -\"- Yes, because the boxplots show no outliers -\"- Yes, because each of the populations are known to be normally distributed -\"- No. because at least one of the boxplots show some outliers -\"- No. because the sample sizes were not big enough to apply the Central Limit Theorem Question 4 4. Is the equal population standard deviation condition met for this test? Below are the sample standard deviations for each group: Blue StDev: 1.53 Green StDev: 1.37 Brown StDev: 1.84 -\"- No. because [largest standard deviation] / [smallest standard deviation] is greater than 2 -\"- Yes, because the largest standard deviation is less than 2. -\"- No. because the largest standard deviation is greater than 2. -\"- Yes, because [largest standard deviation] / [smallest standard deviation] is less than 2. Question 5 5. Assume all the conditions of this test have been met. If the p-value is .010. what can we conclude at o = 0.05? -\"- Fail to reject the null hypothesis and conclude that at least one mean differs from the other means. -\"- Reject the null hypothesis and conclude that at least one mean differs from the other means. -\"- Fail to reject the null hypothesis and conclude that there is insufcient evidence to say that the means are not all equal. -\"- Reject the null hypothesis and conclude that there is insufcient evidence to say that the means are not all equal. Question 6 1 pts 6. Suppose a study was being done in which 3 sample means were being compared. Below are confidence intervals of the data from this study. Based on these confidence intervals, would you believe that the samples have been taken from three groups that have the same population means? Why or Why not? Individual 95% Confidence Intervals for Mean Mean StDev Group 1 35 4.587 Group 2 30 5.392 Group 3 25 3.931 o No, because one or more of the confidence intervals do not overlap with any of the others o Yes, because all of the confidence intervals overlap with each other o No, because the mean for sample 2 is obviously lower than the means of the other samples o Yes, because there is no overlapping between confidence intervals Question 7 1 pts 7. True or False: ANOVA falls under a C - Q role-type classification. o True o False
