In a study of memory recall, 5 people were given 10 minutes to memorize a list of 20 words. Each was asked to list as many of the words as he or she could remember both 1 hour and 24 hours later. The result is shown in the following table.
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Number of Words Recalled
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Subject
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1 hour later
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24 hours later
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1
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14
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12
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2
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18
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15
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3
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11
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9
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4
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13
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12
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5
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12
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12
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Is there evidence to suggest that the mean number of words recalled after 1 hour exceeds the mean recall after 24 hours?
Assume we want to use a 0.10 significance level to test the claim.
(a) Identify the null hypothesis and the alternative hypothesis.
(b) Determine the test statistic. Show all work; writing the correct test statistic, without supporting work, will receive no credit.
(c) Determine the P-value for this test. Show all work; writing the correct P-value, without supporting work, will receive no credit.
STAT 200: Introduction to Statistics Final Examination, Spring 2016 OL4 Page 6 of 7
(d) Is there sufficient evidence to support the claim that the mean number of words recalled after 1 hour exceeds the mean recall after 24 hours? Justify your conclusion.
In a study designed to test the effectiveness of acupuncture for treating migraine, 100 patients were randomly selected and treated with acupuncture. After one-month treatment, the number of migraine attacks for the group had a mean of 2 and standard deviation of 1.5. Construct a 95% confidence interval estimate of the mean number of migraine attacks for people treated with acupuncture. Show all work. Just the answer, without supporting work, will receive no credit.
In a pulse rate research, a simple random sample of 40 men results in a mean of 80 beats per minute, and a standard deviation of 11.3 beats per minute. Based on the sample results, the researcher concludes that the pulse rates of men have a standard deviation greater than 10 beats per minutes. Use a 0.05 significance level to test the researcher's claim..
(a) Identify the null hypothesis and alternative hypothesis.
(b) Determine the test statistic. Show all work; writing the correct test statistic, without supporting work, will receive no credit.
(c) Determine the P-value for this test. Show all work; writing the correct P-value, without supporting work, will receive no credit.
(d) Is there sufficient evidence to support the researcher's claim? Explain.
A survey showed that 80% of the 1600 adult respondents believe in global warming. Construct a 95% confidence interval estimate of the proportion of adults believing in global warming. Show all work. Just the answer, without supporting work, will receive no credit.
A study of 10 different weight loss programs involved 500 subjects. Each of the 10 programs had 50 subjects in it. The subjects were followed for 12 months. Weight change for each subject was recorded. Mimi wants to test the claim that the mean weight loss is the same for the 10 programs.
(a) Complete the following ANOVA table with sum of squares, degrees of freedom, and mean square (Show all work):
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Source of Variation
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Sum of Squares (SS)
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Degrees of Freedom (df)
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Mean Square (MS)
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Factor
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Factor
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Error (Within)
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Total
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1100.76
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N/A
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(b) Determine the test statistic. Show all work; writing the correct test statistic, without supporting work, will receive no credit.
(c) Determine the P-value for this test. Show all work; writing the correct P-value, without supporting work, will receive no credit.
(d) Is there sufficient evidence to support the claim that the mean weight loss is the same for the 10 programs at the significance level of 0.05? Explain.
Assume the weights of men are normally distributed with a mean of 172 lbs and a standard deviation of 30 lbs. Show all work. Just the answer, without supporting work, will receive no credit.
(a) Find the 90th percentile for the distribution of men's weights.
(b) What is the probability that a randomly selected man weighs more than 185 lbs?