MATH120 Exams Questions with Answers Graded A+
What is the impact of changing from the 90%
confidence interval to the 99% confidence interval? - A pharmaceutical company is launching a new
ANSWER -The range of values included medication intended to treat epilepsy. Which of the
increases. following would make sense as a null hypothesis
when testing the efficacy of the drug? -
ANSWER -Ho: The drug is not an effective
What does decreasing the standard deviation of the treatment for epilepsy.
sample do to the confidence interval? -
ANSWER -The range of values included
decreases. A pharmaceutical company is launching a new
medication intended to treat epilepsy. The company
performs a study that maintains the null hypothesis.
What is the impact of decreasing the sample size? - What is the finding of the company? -
ANSWER -The range of values included ANSWER -The evidence suggests that the drug
increases. is not an effective treatment against epilepsy.
Which accurately describes widening the range of A supplier of parts to the automobile industry is
the confidence interval (by changing the confidence launching a new brake pad intended to wear down
level)? - ANSWER -The range is wider so the more slowly while delivering the same performance.
certainty is higher. The company performs a study that incorrectly
rejects the null hypothesis. What type of error is this?
- ANSWER -Type 1: The supplier rejected the
A delivery company provides expected time of null when it should not have.
arrival. The company wants to provide an accurate
suggestion with a 90% confidence level. If the
sample size is 50, the sample average is 35 minutes, A supplier of parts to the automobile industry is
the standard deviation is 10 minutes, and the z-score launching a new brake pad intended to wear down
is 1.65, what is the standard error of the mean? - more slowly while delivering the same performance.
ANSWER -1.41 The company performs a study that incorrectly
maintains the null hypothesis. What type of error is
this? - ANSWER -Type 2: The supplier
A delivery company provides expected time of maintained the null when it should have rejected it.
arrival. The company wants to provide an accurate
suggestion with a 90% confidence level. If the
sample size is 50, the sample average is 35 minutes, When assessing the significance of a study, we're
the standard deviation is 10 minutes, and the z-score asking: - ANSWER -What is the likelihood that
is 1.65, what is the margin of error? - ANSWER - we incorrectly reject the null?
2.33
You're surprised to learn that instead of ~$100, a 0.30
A delivery company provides expected time of carat costs ~$800 carats. Which explanation would
arrival. The company wants to provide an accurate make sense? - ANSWER -The linear regression
suggestion with a 90% confidence level. If the is not accurate at predicting the cost of diamonds
sample size is 50, the sample average is 35 minutes, below 0.40 carats.
the standard deviation is 10 minutes, and the z-score There is a fixed cost associated with procuring the
is 1.65, what is the confidence interval? - diamond and offering it for sale, meaning that small
ANSWER -(32.67, 37.33) diamonds have a relatively high price.
The diamond is very high quality as measured by
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, MATH120 Exams Questions with Answers Graded A+
other metrics (e.g., cut, clarity, color). If the r-squared of the regression line comparing the
**All of the above.** age of a used motorcycle to its cost is 64%, what is
the correlation coefficient? - ANSWER --0.80
If a residual is negative, what does it mean about the
observed value? - ANSWER -The predicted Using the test scores in the table below, what is the
value is greater than the observed value. variance of the scores on the exam? (Round your
answer to the nearest whole number.)
96 92 91 90 87 86 86 83 82 77 - ANSWER -27
If the expected value of a diamond is $3,500, but the
observed value is $3,800, what is the residual? -
ANSWER -$300 Using the test scores in the table below, what is the
standard deviation of the scores on the exam?
(Round your answer to the nearest whole number.)
If the correlation between the price of two stocks is 96 92 91 90 87 86 86 83 82 77 - ANSWER -5
0.83, what does this indicate? - ANSWER - Determine that the average score is 87%
Strong positive correlation Calculate all of the differences between the scores
and the average to get 9, 5, 4, 3, 0, -1, -1, -4, -5, -10
Square all of the differences to get 81, 25, 16, 9, 0, 1,
If the coefficient of determination between the price 1, 16, 25, 100
of a house and it square footage is 65%, what Average the squared differences to get 27.4 as the
percentage of the variation in the price of the house variance
is explained by its size? - ANSWER -65% Take the square root of the variance to get 5.23 as the
standard deviation
Round 5.23 to the nearest whole number to get 5
If the correlation coefficient between the price of a Answer: 5
car and its mileage is 60%, what percentage of the
price of the car is explained by its mileage? -
ANSWER -36% Assume that 500,000 people take the GED exam
(high school proficiency exam) each year and their
scores form a normal distribution. If Danny scores
If the regression line comparing the age of a used car two standard deviations below the mean, what
to its price has the equation c = -3000a + 36000, percentile is he? - ANSWER -2.5th
what is the expected cost of an 8-year-old car? -
ANSWER -$12,000
Assume that 500,000 people take the GED exam
(high school proficiency exam) each year and their
If the regression line comparing the age of a used car scores form a normal distribution. If Tara scores one
to its price has the equation c = -3000a + 36000 and standard deviation above the mean, what percentile
the residual is $3,000, what is the observed cost of is she? - ANSWER -84th
an 8-year-old car? - ANSWER -$15,000
Assume that 20 people take a math test, which is not
If the regression line comparing the age of a used car enough for a normal distribution to form. If Conrad
to its price has the equation c = -3000a + 36000, scores three standard deviations above the mean,
what is the expected age of a car that costs $27,000? what percentile is he? - ANSWER -Not enough
- ANSWER -3 years information to determine.
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What is the impact of changing from the 90%
confidence interval to the 99% confidence interval? - A pharmaceutical company is launching a new
ANSWER -The range of values included medication intended to treat epilepsy. Which of the
increases. following would make sense as a null hypothesis
when testing the efficacy of the drug? -
ANSWER -Ho: The drug is not an effective
What does decreasing the standard deviation of the treatment for epilepsy.
sample do to the confidence interval? -
ANSWER -The range of values included
decreases. A pharmaceutical company is launching a new
medication intended to treat epilepsy. The company
performs a study that maintains the null hypothesis.
What is the impact of decreasing the sample size? - What is the finding of the company? -
ANSWER -The range of values included ANSWER -The evidence suggests that the drug
increases. is not an effective treatment against epilepsy.
Which accurately describes widening the range of A supplier of parts to the automobile industry is
the confidence interval (by changing the confidence launching a new brake pad intended to wear down
level)? - ANSWER -The range is wider so the more slowly while delivering the same performance.
certainty is higher. The company performs a study that incorrectly
rejects the null hypothesis. What type of error is this?
- ANSWER -Type 1: The supplier rejected the
A delivery company provides expected time of null when it should not have.
arrival. The company wants to provide an accurate
suggestion with a 90% confidence level. If the
sample size is 50, the sample average is 35 minutes, A supplier of parts to the automobile industry is
the standard deviation is 10 minutes, and the z-score launching a new brake pad intended to wear down
is 1.65, what is the standard error of the mean? - more slowly while delivering the same performance.
ANSWER -1.41 The company performs a study that incorrectly
maintains the null hypothesis. What type of error is
this? - ANSWER -Type 2: The supplier
A delivery company provides expected time of maintained the null when it should have rejected it.
arrival. The company wants to provide an accurate
suggestion with a 90% confidence level. If the
sample size is 50, the sample average is 35 minutes, When assessing the significance of a study, we're
the standard deviation is 10 minutes, and the z-score asking: - ANSWER -What is the likelihood that
is 1.65, what is the margin of error? - ANSWER - we incorrectly reject the null?
2.33
You're surprised to learn that instead of ~$100, a 0.30
A delivery company provides expected time of carat costs ~$800 carats. Which explanation would
arrival. The company wants to provide an accurate make sense? - ANSWER -The linear regression
suggestion with a 90% confidence level. If the is not accurate at predicting the cost of diamonds
sample size is 50, the sample average is 35 minutes, below 0.40 carats.
the standard deviation is 10 minutes, and the z-score There is a fixed cost associated with procuring the
is 1.65, what is the confidence interval? - diamond and offering it for sale, meaning that small
ANSWER -(32.67, 37.33) diamonds have a relatively high price.
The diamond is very high quality as measured by
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, MATH120 Exams Questions with Answers Graded A+
other metrics (e.g., cut, clarity, color). If the r-squared of the regression line comparing the
**All of the above.** age of a used motorcycle to its cost is 64%, what is
the correlation coefficient? - ANSWER --0.80
If a residual is negative, what does it mean about the
observed value? - ANSWER -The predicted Using the test scores in the table below, what is the
value is greater than the observed value. variance of the scores on the exam? (Round your
answer to the nearest whole number.)
96 92 91 90 87 86 86 83 82 77 - ANSWER -27
If the expected value of a diamond is $3,500, but the
observed value is $3,800, what is the residual? -
ANSWER -$300 Using the test scores in the table below, what is the
standard deviation of the scores on the exam?
(Round your answer to the nearest whole number.)
If the correlation between the price of two stocks is 96 92 91 90 87 86 86 83 82 77 - ANSWER -5
0.83, what does this indicate? - ANSWER - Determine that the average score is 87%
Strong positive correlation Calculate all of the differences between the scores
and the average to get 9, 5, 4, 3, 0, -1, -1, -4, -5, -10
Square all of the differences to get 81, 25, 16, 9, 0, 1,
If the coefficient of determination between the price 1, 16, 25, 100
of a house and it square footage is 65%, what Average the squared differences to get 27.4 as the
percentage of the variation in the price of the house variance
is explained by its size? - ANSWER -65% Take the square root of the variance to get 5.23 as the
standard deviation
Round 5.23 to the nearest whole number to get 5
If the correlation coefficient between the price of a Answer: 5
car and its mileage is 60%, what percentage of the
price of the car is explained by its mileage? -
ANSWER -36% Assume that 500,000 people take the GED exam
(high school proficiency exam) each year and their
scores form a normal distribution. If Danny scores
If the regression line comparing the age of a used car two standard deviations below the mean, what
to its price has the equation c = -3000a + 36000, percentile is he? - ANSWER -2.5th
what is the expected cost of an 8-year-old car? -
ANSWER -$12,000
Assume that 500,000 people take the GED exam
(high school proficiency exam) each year and their
If the regression line comparing the age of a used car scores form a normal distribution. If Tara scores one
to its price has the equation c = -3000a + 36000 and standard deviation above the mean, what percentile
the residual is $3,000, what is the observed cost of is she? - ANSWER -84th
an 8-year-old car? - ANSWER -$15,000
Assume that 20 people take a math test, which is not
If the regression line comparing the age of a used car enough for a normal distribution to form. If Conrad
to its price has the equation c = -3000a + 36000, scores three standard deviations above the mean,
what is the expected age of a car that costs $27,000? what percentile is he? - ANSWER -Not enough
- ANSWER -3 years information to determine.
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