# Quiz 3_MATH302 - Question 1 of 10 1.0 Points A sample of 25...

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Quiz 3_MATH302

Question 2   of 10 1.0 Points A previous study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams . How many nickels does a coin counter manufacturer need to weigh so that she can be 98 % confident that her sample mean is within 25 milligrams of the true average weight of a nickel ?
A. 36
B. 196
C. 239
D. 139
Question 1 of 101.0 PointsA sample of 25 different payroll departments found that the employees worked an average of 310.3 days a year with a standard deviation of 23.8 days. What is the 90% confidence interval for the average days worked by employees in all payroll departments?A. 301.0 < 319.6B. 298.0 < 322.6C. 302.2 < 318.4D. 314.1 < 316.8Answer Key:
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CQuestion 2 of 101.0 PointsA previous study of nickels showed that the standard deviation of the weight of nickels is 150 milligrams. How many nickels does a coin counter manufacturer need to weigh so that she can be 98% confident that her sample mean is within 25 milligrams of the true average weight of a nickel?
BQuestion 3 of 101.0 Points
A food snack manufacturer samples 15 bags of pretzels off the assembly line and weighed their contents. If the sample mean is 10.0 and the sample standard deviation is 0.15, find the 95% confidence interval estimate for the true mean.
D
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