Problem #6: An observational study of Alzheimer's disease (AD) obtained data from 16 AD patients exhibiting...

 

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Problem #6: An observational study of Alzheimer's disease (AD) obtained data from 16 AD patients exhibiting moderate dementia and selected a group of 9 control individuals without AD. AD is a progressive neurodegenerative disease of the elderly and advancing age is known to be a primary risk factor in AD diagnosis. Therefore, it was crucial for the study's credibility to examine whether the ages in the AD group might be significantly different than in the control group. The ages of the subjects in years are summarized in the R Output below. Variable Alzheimers 16 79.76 Control n Mean sd Minimum 9 6.50 68.33 12.93 77.00 54.00 Q1 Median Q3 Maximum 79.25 87.00 92.25 93.00 56.00 65.00 82.00 89.00 We want to test if the average age in the Alzheimer's group is significantly different than the control group. (a) What is the null hypothesis? (b) Find the value of the test statistic. (c) Find the 5% critical value. (d) What is the conclusion of the hypothesis test? (A) Ho (B) Ho: <2 (C) Ho: 12 (D) H: #12 (E) H2 (F) Ho 1=2 Problem #6(a): F null hypothesis Problem #6(b): Problem #6(c): test statistic (correct to 3 decimals) critical value (correct to 3 decimals) (A) Reject Ho since the absolue value of the answer in (b) is less than the answer in (c). (B) Reject Ho since the p-value is equal to 0.0132 which is less than .05. (C) Do not reject Ho since the p-value is equal to 0.0066 which is less than .05. (D) Do not reject Ho since the absolue value of the answer in (b) is less than the answer in (c). (E) Do not reject Ho since the absolue value of the answer in (b) is greater than the answer in (c). (F) Do not reject Ho since the p-value is equal to 0.0132 which is less than .05. (G) Reject Ho since the absolue value of the answer in (b) is greater than the answer in (c). (H) Reject Ho since the p-value is equal to 0.0066 which is less than .05. Problem #6(d): Select conclusion Just Save Submit Problem #6 for Grading Problem #6 Attempt #1 Attempt #2 Attempt #3 Your Answer: 6(a) F 6(a) 6(a) 6(b) 0.145 6(b) 6(b) 6(c) 1.978 6(c) 6(c) 6(d) D 6(d) 6(d) Your Mark: 6(a) 2/2 6(a) 6(a) 6(b) 0/2x 6(b) 6(b) 6(c) 0/2x 6(c) 6(c) 6(d) 0/2x 6(d) 6(d) Problem #6: An observational study of Alzheimer's disease (AD) obtained data from 16 AD patients exhibiting moderate dementia and selected a group of 9 control individuals without AD. AD is a progressive neurodegenerative disease of the elderly and advancing age is known to be a primary risk factor in AD diagnosis. Therefore, it was crucial for the study's credibility to examine whether the ages in the AD group might be significantly different than in the control group. The ages of the subjects in years are summarized in the R Output below. Variable Alzheimers 16 79.76 Control n Mean sd Minimum 9 6.50 68.33 12.93 77.00 54.00 Q1 Median Q3 Maximum 79.25 87.00 92.25 93.00 56.00 65.00 82.00 89.00 We want to test if the average age in the Alzheimer's group is significantly different than the control group. (a) What is the null hypothesis? (b) Find the value of the test statistic. (c) Find the 5% critical value. (d) What is the conclusion of the hypothesis test? (A) Ho (B) Ho: <2 (C) Ho: 12 (D) H: #12 (E) H2 (F) Ho 1=2 Problem #6(a): F null hypothesis Problem #6(b): Problem #6(c): test statistic (correct to 3 decimals) critical value (correct to 3 decimals) (A) Reject Ho since the absolue value of the answer in (b) is less than the answer in (c). (B) Reject Ho since the p-value is equal to 0.0132 which is less than .05. (C) Do not reject Ho since the p-value is equal to 0.0066 which is less than .05. (D) Do not reject Ho since the absolue value of the answer in (b) is less than the answer in (c). (E) Do not reject Ho since the absolue value of the answer in (b) is greater than the answer in (c). (F) Do not reject Ho since the p-value is equal to 0.0132 which is less than .05. (G) Reject Ho since the absolue value of the answer in (b) is greater than the answer in (c). (H) Reject Ho since the p-value is equal to 0.0066 which is less than .05. Problem #6(d): Select conclusion Just Save Submit Problem #6 for Grading Problem #6 Attempt #1 Attempt #2 Attempt #3 Your Answer: 6(a) F 6(a) 6(a) 6(b) 0.145 6(b) 6(b) 6(c) 1.978 6(c) 6(c) 6(d) D 6(d) 6(d) Your Mark: 6(a) 2/2 6(a) 6(a) 6(b) 0/2x 6(b) 6(b) 6(c) 0/2x 6(c) 6(c) 6(d) 0/2x 6(d) 6(d)