MGSC 291 (Exam 2) Questions And
Answers Verified 100% Correct
What do you need to find the confidence interval of success for the population
proportion? - ANSWER -1. the distribution of should be approx. normal
2. mean of the normal distribution is p
3. std. dev. = squr. root (p(1-p)/n)
What do you need to see if the confidence interval of a sample statistics is large
enough? - ANSWER -1. sample mean is approx. normal
2. population mean is normally distributed
3. std. dev. is sigma/squ. root of n
Assuming the std. dev. is unknown you must have.... - ANSWER -independent
observations from a large population and the sample mean (x bar) has a normal
distribution
When estimating n for a sample size you must:
a) round down to a whole number
b) round two decimal places
c) round up to a whole number
d) round to four decimal places - ANSWER -c) round up to a whole number to
ensure the desired level of confidence at the desired MOE
H0 (null hypothesis) - ANSWER -A statement about the value of a PARAMETER
Ho (null hypothesis) always contains what? - ANSWER -an equal sign (=,<,>)
What are the two parameters used in hypothesis testing? - ANSWER -proportion
and mean
P-value - ANSWER -the probability, given that the null hypothesis is true, of
observing a test statistic that's extreme or more extreme in the direction of the
alternative hypothesis (evidence against Ho)
small p-value indicates: - ANSWER -a rare result if the null hypothesis was true
, How much evidence is needed to reject the null hypothesis? - ANSWER -depends;
compare the P-value to the significance level (alpha)
What is the level of significance? - ANSWER -P <= alpha, reject Ho (find for Ha)
P> alpha, fail to reject Ho (do not find for Ha)
The conclusion of the hypothesis should always be in terms of _____?
a) the significance level
b) alternative hypothesis
c) null hypothesis
d) none of the above - ANSWER -b) alternative hypothesis
Steps for Hypothesis Testing - ANSWER -1. set alpha (significance level)
2. state hypothesis
3. gather data from sample & compute test statistic
4. compute P-value
5. make decision (in terms of Ho)
6. State conclusion
*check assumptions of independence & normality
two-tailed hypothesis - ANSWER -both directions of an effect or relationship are
considered in the alternative hypothesis of the test
When we reject the null hypothesis when it is actually false, we have committed
_________. - ANSWER -no error
For a given sample size n,
________________________________________________________. - ANSWER
-decreasing the probability of a Type I error α will increase the probability of a
Type II error β
Correct
Taking a large sample helps with determining what about the distribution of the
population? - ANSWER -the distribution is normal
You reject H0 if: - ANSWER -P<=alpha
Fail to reject H0 if: - ANSWER -P>alpha
Answers Verified 100% Correct
What do you need to find the confidence interval of success for the population
proportion? - ANSWER -1. the distribution of should be approx. normal
2. mean of the normal distribution is p
3. std. dev. = squr. root (p(1-p)/n)
What do you need to see if the confidence interval of a sample statistics is large
enough? - ANSWER -1. sample mean is approx. normal
2. population mean is normally distributed
3. std. dev. is sigma/squ. root of n
Assuming the std. dev. is unknown you must have.... - ANSWER -independent
observations from a large population and the sample mean (x bar) has a normal
distribution
When estimating n for a sample size you must:
a) round down to a whole number
b) round two decimal places
c) round up to a whole number
d) round to four decimal places - ANSWER -c) round up to a whole number to
ensure the desired level of confidence at the desired MOE
H0 (null hypothesis) - ANSWER -A statement about the value of a PARAMETER
Ho (null hypothesis) always contains what? - ANSWER -an equal sign (=,<,>)
What are the two parameters used in hypothesis testing? - ANSWER -proportion
and mean
P-value - ANSWER -the probability, given that the null hypothesis is true, of
observing a test statistic that's extreme or more extreme in the direction of the
alternative hypothesis (evidence against Ho)
small p-value indicates: - ANSWER -a rare result if the null hypothesis was true
, How much evidence is needed to reject the null hypothesis? - ANSWER -depends;
compare the P-value to the significance level (alpha)
What is the level of significance? - ANSWER -P <= alpha, reject Ho (find for Ha)
P> alpha, fail to reject Ho (do not find for Ha)
The conclusion of the hypothesis should always be in terms of _____?
a) the significance level
b) alternative hypothesis
c) null hypothesis
d) none of the above - ANSWER -b) alternative hypothesis
Steps for Hypothesis Testing - ANSWER -1. set alpha (significance level)
2. state hypothesis
3. gather data from sample & compute test statistic
4. compute P-value
5. make decision (in terms of Ho)
6. State conclusion
*check assumptions of independence & normality
two-tailed hypothesis - ANSWER -both directions of an effect or relationship are
considered in the alternative hypothesis of the test
When we reject the null hypothesis when it is actually false, we have committed
_________. - ANSWER -no error
For a given sample size n,
________________________________________________________. - ANSWER
-decreasing the probability of a Type I error α will increase the probability of a
Type II error β
Correct
Taking a large sample helps with determining what about the distribution of the
population? - ANSWER -the distribution is normal
You reject H0 if: - ANSWER -P<=alpha
Fail to reject H0 if: - ANSWER -P>alpha
