Statistics chapter 7 Exam Questions and Answers 100% Correct
A single number that estimates the value of an unknown parameter is called a _ estimate - Answers
Point
The margin of error is the product of the standard error and the _ - Answers Critical value
In the confidence interval 24.3 +- 1.2 the quantity 1.2 is called the _ - Answers Margin of error
If we increase the confidence level and keep the sample size the same, we _ the margin of error -
Answers Increase
The confidence level is the proportion of all possible samples for which the confidence interval will cover
the true values - Answers True
To construct a confidence interval for a population mean, we add and subtract the critical value from
the point estimate - Answers False, margin of error
Increasing the sample size while keeping the confidence level the same will result in a narrower
confidence interval - Answers True
If a 95% confidence interval for a population mean is 1.7<U<2.4, then the probability is 0.95 that the
mean is between 1.7 and 2.3 - Answers False
When constructing a confidence interval for a population mean u from a sample of size 12, the number
of degrees of freedom for the critical value ta/2 is_ - Answers 11
When the number of degrees of freedom is large, the student's t distribution is close to _ distribution. -
Answers Normal
The student's t curve is less spread out than the standard normal curve. - Answers False more
The student's t distribution should not be used to find a confidence interval for u if outliers are
presented in a small sample. - Answers True
If p^ is the sample proportion and n is the sample size, then square root p^ (1-p^) over n is the _ -
Answers Standard error
To estimate the necessary sample size when no value of p^ is available, we use p^=_ - Answers 0.5
If we estimate the necessary sample size and no value for p^ is available, the estimated sample size will
be larger than if a value for p^ were available. - Answers True
The margin of error does not depend of sample size - Answers False does
Point estimate - Answers X-, s, s^2, p^
Standard error - Answers O/square root n
A single number that estimates the value of an unknown parameter is called a _ estimate - Answers
Point
The margin of error is the product of the standard error and the _ - Answers Critical value
In the confidence interval 24.3 +- 1.2 the quantity 1.2 is called the _ - Answers Margin of error
If we increase the confidence level and keep the sample size the same, we _ the margin of error -
Answers Increase
The confidence level is the proportion of all possible samples for which the confidence interval will cover
the true values - Answers True
To construct a confidence interval for a population mean, we add and subtract the critical value from
the point estimate - Answers False, margin of error
Increasing the sample size while keeping the confidence level the same will result in a narrower
confidence interval - Answers True
If a 95% confidence interval for a population mean is 1.7<U<2.4, then the probability is 0.95 that the
mean is between 1.7 and 2.3 - Answers False
When constructing a confidence interval for a population mean u from a sample of size 12, the number
of degrees of freedom for the critical value ta/2 is_ - Answers 11
When the number of degrees of freedom is large, the student's t distribution is close to _ distribution. -
Answers Normal
The student's t curve is less spread out than the standard normal curve. - Answers False more
The student's t distribution should not be used to find a confidence interval for u if outliers are
presented in a small sample. - Answers True
If p^ is the sample proportion and n is the sample size, then square root p^ (1-p^) over n is the _ -
Answers Standard error
To estimate the necessary sample size when no value of p^ is available, we use p^=_ - Answers 0.5
If we estimate the necessary sample size and no value for p^ is available, the estimated sample size will
be larger than if a value for p^ were available. - Answers True
The margin of error does not depend of sample size - Answers False does
Point estimate - Answers X-, s, s^2, p^
Standard error - Answers O/square root n
