The owner of a local golf course wants to determine the average
age of the golfers that play on the course in relation to the
average age in the area. According to the most recent census, the
town has an average age of 23.44. In a random sample of 26 golfers
that visited his course, the sample mean was 30.63 and the standard
deviation was 8.771. Using this information, the owner calculated
the confidence interval of (25.84, 35.42) with a confidence level
of 99%. Which of the following statements is the best
conclusion?
Question 5 options:
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1)
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We are 99% confident that the average age of all golfers that
play on the golf course is greater than 23.44 |
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2)
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We are 99% confident that the average age of all golfers that
play on the golf course is less than 23.44 |
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3)
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The average age of all golfers does not significantly differ
from 23.44. |
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4)
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The percentage of golfers with an age greater than 23.44 is
99%. |
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5)
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We cannot determine the proper interpretation based on the
information given. |
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Question 6 (1 point)
Researchers at a metals lab are testing a new alloy for use in
high end electronics. The alloy is very expensive to make so their
budget for testing is limited. The researchers need to estimate the
average force required to bend a piece of the alloy to a 90 degree
angle. From previous tests, the standard deviation is known to be
34.632 Newtons. In order to estimate the true mean within a margin
of error of 9.703 Newtons with 99% confidence, how many samples
would need to be tested?
Question 6 options:
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1)
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We do not have enough information to answer this question since
we were not given the sample mean. |
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Question 7 (1 point)
A pharmaceutical company is testing a new drug to increase
memorization ability. It takes a sample of individuals and splits
them randomly into two groups. After the drug regimen is completed,
all members of the study are given a test for memorization ability
with higher scores representing a better ability to memorize. Those
28 participants on the drug had an average test score of 28.396 (SD
= 4.142) while those 26 participants not on the drug had an average
score of 40.736 (SD = 5.24). You use this information to create a
90% confidence interval for the difference in average test score.
What is the margin of error? Assume the population standard
deviations are equal.
Question 7 options:
Question 8 (1 point)
In a consumer research study, several Meijer and Walmart stores
were surveyed at random and the average basket price was recorded
for each. It was found that the average basket price for 8 Meijer
stores was $132.15 with a standard deviation of $24.701. 11 Walmart
stores had an average basket price of $156.97 with a standard
deviation of $19.049. Construct a 99% confidence interval for the
difference between the true average basket prices (Meijer -
Walmart). You can assume that the standard deviations of the two
populations are statistically similar.
Question 8 options:
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4)
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We only have the sample means, we need to know the population
means in order to calculate a confidence interval. |
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Question 9 (1 point)
Independent random samples are taken at a university to compare
the average GPA of seniors to the average GPA of sophomores. Given
a 95% confidence interval for the difference between the true
average GPAs (seniors - sophomores) of (0, 1.13), what can you
conclude?
Question 9 options:
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1)
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We are 95% confident that the difference between the two sample
GPAs falls within the interval. |
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2)
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We are 95% confident that the average GPA of seniors is greater
than the average GPA of sophomores. |
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3)
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There is no significant difference between the true average GPA
for seniors and sophomores. |
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4)
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We do not have enough information to make a conclusion. |
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5)
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We are 95% confident that the average GPA of seniors is less
than the average GPA of sophomores. |
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Question 10 (1 point)
The owner of a local golf course wants to estimate the
difference between the average ages of males and females that play
on the golf course. He randomly samples 24 men and 21 women that
play on his course. He finds the average age of the men to be
37.722 with a standard deviation of 7.091. The average age of the
women was 32.214 with a standard deviation of 5.243. He uses this
information to calculate a 99% confidence interval for the
difference in means, (0.436, 10.58). The best interpretation of
this interval is which of the following statements?
Question 10 options:
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1)
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We are certain that the difference between the average age of
all men and all women is between 0.436 and 10.58. |
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2)
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We are 99% confident that the difference between the average
age of the men and women surveyed is between 0.436 and 10.58 |
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3)
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We do not know the population means so we do not have enough
information to make an interpretation. |
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4)
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We are 99% sure that the average age difference between all
males and females is between 0.436 and 10.58. |
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5)
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We are 99% confident that the difference between the average
age of all men and all women who play golf at the course is between
0.436 and 10.58 |
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