Statistics Exam 3 with Complete
Solutions
α: - ANSWER-The symbol for level of significance (probability of a type I error).
Alternative Hypothesis - ANSWER-The hypothesis that the researcher wants to
prove or verify; a statement about the value of a parameter that is either "less than,"
"greater than," "not equal to."
β: - ANSWER-The probability of failing to reject a false null hypothesis (probability
of a type II error).
Confidence Interval - ANSWER-An estimate of the value of a parameter in interval
form with an associated level of confidence; in other words, a list of reasonable or
plausible values for the parameter based on the value of a statistic. E.g. a confidence
interval for µ gives a list of possible values
that µ could be based on the sample mean
Confidence Level - ANSWER-The percent of the time that the confidence interval
estimation procedure will give you intervals containing the value of the parameter being
estimated. (Note: This can only be defined in terms of probability as follows: ―The
probability that the confidence interval to be computed (before data are gathered) will
contain the value of the
parameter. After data are collected, level of confidence is no longer a probability
because a calculated confidence interval either contains the value of the parameter or it
doesn't.)
Degrees of Freedom - ANSWER-A characteristic of the t-distribution (e.g. n - 1 for
a one-sample t); a measure of the amount of information available for estimating σ
using s.
For a two-sample, it is (n1 + n2) - 2. (I think)
Fail to reject Ho - ANSWER-The appropriate statistical conclusion when the P-value
is greater than α.
Inference - ANSWER-Using results about sample statistics to draw conclusions
about population parameters.
Interval Estimation - ANSWER-estimate an unknown parameter using an interval
of values that is likely to contain the true value of that parameter
Level of significance (symbolized by α): - ANSWER-The probability of rejecting a true
null hypothesis; equivalently, the largest risk a researcher is willing
Solutions
α: - ANSWER-The symbol for level of significance (probability of a type I error).
Alternative Hypothesis - ANSWER-The hypothesis that the researcher wants to
prove or verify; a statement about the value of a parameter that is either "less than,"
"greater than," "not equal to."
β: - ANSWER-The probability of failing to reject a false null hypothesis (probability
of a type II error).
Confidence Interval - ANSWER-An estimate of the value of a parameter in interval
form with an associated level of confidence; in other words, a list of reasonable or
plausible values for the parameter based on the value of a statistic. E.g. a confidence
interval for µ gives a list of possible values
that µ could be based on the sample mean
Confidence Level - ANSWER-The percent of the time that the confidence interval
estimation procedure will give you intervals containing the value of the parameter being
estimated. (Note: This can only be defined in terms of probability as follows: ―The
probability that the confidence interval to be computed (before data are gathered) will
contain the value of the
parameter. After data are collected, level of confidence is no longer a probability
because a calculated confidence interval either contains the value of the parameter or it
doesn't.)
Degrees of Freedom - ANSWER-A characteristic of the t-distribution (e.g. n - 1 for
a one-sample t); a measure of the amount of information available for estimating σ
using s.
For a two-sample, it is (n1 + n2) - 2. (I think)
Fail to reject Ho - ANSWER-The appropriate statistical conclusion when the P-value
is greater than α.
Inference - ANSWER-Using results about sample statistics to draw conclusions
about population parameters.
Interval Estimation - ANSWER-estimate an unknown parameter using an interval
of values that is likely to contain the true value of that parameter
Level of significance (symbolized by α): - ANSWER-The probability of rejecting a true
null hypothesis; equivalently, the largest risk a researcher is willing
