MGSC 291 exam 2 Questions and
Answers Graded A+
what do we decide if the p val is lower than the significance level? - Correct
answer-we reject the null hypothesis
what if the p val is greater than the significance level? - Correct answer-we do not
have sufficient evidence to reject the null hypothesis
what is the null hypothesis? - Correct answer-what we beleive to be true or what
was beleived to be common knowledge
what is the def of an alternaitve hypothsis - Correct answer-what we want to test,
testing the opposite of the null to find out if the null is actually false
in a qq plot, if the points dont exactly make a perfect line, then what would deem it
normal - Correct answer-a large enough sample size per the central limit theorem
a confidence interval is given to find the proportion of a paramter that belongs to a
certain group
(0.34892, 0.39242)
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, interpret the interval - Correct answer-we are 95% confident that the proportion
lies between 34.89% and 39.24%
what do you do to find the confidence interval for one mean? give the R code -
Correct answer-since don't have the variance, conduct t test
t.test(data$column, conf. level=0.99)
what do you do if want to test whether the mean we have is legit or whether it's
actually higher or lower - Correct answer-
t.test(data$column,mu=(x),alternative="greater")
or "less than" or "two sided"
how do you calculate the p value after running a hyp test - Correct answer-1-
pt(t,df)
two sided
2*(1-pt(t,df))
how do you make a qq plot and what is it for? - Correct answer-qqnorm(resid(fit))
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Answers Graded A+
what do we decide if the p val is lower than the significance level? - Correct
answer-we reject the null hypothesis
what if the p val is greater than the significance level? - Correct answer-we do not
have sufficient evidence to reject the null hypothesis
what is the null hypothesis? - Correct answer-what we beleive to be true or what
was beleived to be common knowledge
what is the def of an alternaitve hypothsis - Correct answer-what we want to test,
testing the opposite of the null to find out if the null is actually false
in a qq plot, if the points dont exactly make a perfect line, then what would deem it
normal - Correct answer-a large enough sample size per the central limit theorem
a confidence interval is given to find the proportion of a paramter that belongs to a
certain group
(0.34892, 0.39242)
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
, interpret the interval - Correct answer-we are 95% confident that the proportion
lies between 34.89% and 39.24%
what do you do to find the confidence interval for one mean? give the R code -
Correct answer-since don't have the variance, conduct t test
t.test(data$column, conf. level=0.99)
what do you do if want to test whether the mean we have is legit or whether it's
actually higher or lower - Correct answer-
t.test(data$column,mu=(x),alternative="greater")
or "less than" or "two sided"
how do you calculate the p value after running a hyp test - Correct answer-1-
pt(t,df)
two sided
2*(1-pt(t,df))
how do you make a qq plot and what is it for? - Correct answer-qqnorm(resid(fit))
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
