I've been looking for a clear explanation for about an hour and a half now. I've tried researching on the internet, reading my book and notes, and asking my friends, but I'm having trouble understanding how to figure this out!
The claim is: MIT claims that statisticians make $100,000 a year with a college degree. A sample of 30 statisticians shows their average salary to be $96,000 with s=$2,000.
1. What is the critical value(s) if alpha=.01?
Can someone please explain to me the steps of what I need to do because I really don't understand.
I have a TI-84 calculator if you could explain it on the calculator!
2. Find the appropriate critical values for case/
Null Hypothesis: Mu=27 n=35 and alpha=.10
Thank you so much in advance.
The claim is: MIT claims that statisticians make $100,000 a year with a college degree. A sample of 30 statisticians shows their average salary to be $96,000 with s=$2,000.
1. What is the critical value(s) if alpha=.01?
Can someone please explain to me the steps of what I need to do because I really don't understand.
I have a TI-84 calculator if you could explain it on the calculator!
2. Find the appropriate critical values for case/
Null Hypothesis: Mu=27 n=35 and alpha=.10
Thank you so much in advance.
-
forget the calculator - it's better to understand what's going on.
1) the question doesnt ask for the actual hypothesis test, but here it is. By the way, the std dev s of $2,000 looks unreasonably low - is it correct? (sure it isnt $20,000?).
std dev. of sampling distribution of mean is s/sqrt(n) = 2,000/sqrt(30)=365.15.
now calculate the difference from the expected mean (100,000) in units of std dev.
(96,000 - 100,000)/365.15 = -10.95
now, look at a t-dist. table for 30-1=29 degrees of freedom (cutting off .005 in each tail for a 2-tail test) - the critical value is 2.756 (and we would reject the hypothesis that the mean is $100,000).
2) deg. freedom= 35-1=34.
critical value from t-table for alpha=.10 (you didnt specify whether a 1 or 2 tail test)
is 1.691 for a 2-tail test.
1) the question doesnt ask for the actual hypothesis test, but here it is. By the way, the std dev s of $2,000 looks unreasonably low - is it correct? (sure it isnt $20,000?).
std dev. of sampling distribution of mean is s/sqrt(n) = 2,000/sqrt(30)=365.15.
now calculate the difference from the expected mean (100,000) in units of std dev.
(96,000 - 100,000)/365.15 = -10.95
now, look at a t-dist. table for 30-1=29 degrees of freedom (cutting off .005 in each tail for a 2-tail test) - the critical value is 2.756 (and we would reject the hypothesis that the mean is $100,000).
2) deg. freedom= 35-1=34.
critical value from t-table for alpha=.10 (you didnt specify whether a 1 or 2 tail test)
is 1.691 for a 2-tail test.