QMB 3250 Exam 2 (Computing by Hand)questions with correct solutions

QMB 3250 Exam 2 (Computing by
Hand)questions with correct solutions

Test Statistic for One Slope (SLR) - ANSWER: ➡ b1 - 0/SE(b1)
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Test Statistic for One Slope (SLR) EXAMPLE
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A local ice cream store wanted to see if there was a linear relationship between average
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temperature on any given day and their ice cream sales. After recording sales and
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temperatures for 15 randomly selected days they calculated b1 to be equal to 5.59 and a
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standard error of b1 to be equal to 2.04. - ANSWER: ➡ 5.59/2.04
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TS= 2.74 o




Confidence Interval for One Slope (SLR) - ANSWER: ➡ b1 +- t*n-2 SE(b1)
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Test Statistic for Population Correlation - ANSWER: ➡ r sqrt n-2/1-r^2
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Test Statistic for Population Correlation EXAMPLE
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A Bank manager is studying the correlation between number of withdrawals per customer in a
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quarter to the number of deposits per customer in a quarter. An analyst on his team provided
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him with the following output from a trusted data set.
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n = 60 o o




r = 0.9204
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Calculate the test statistic for the significance test to determine if the population correlation
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coefficient is different from zero. Round to the nearest two decimal places. - ANSWER: ➡
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0.9204 sqrt 60-2/1-0.9204^2
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0.9204 sqrt 58/0.153 o o