Ch 9
Ch 10
Ch 14
100
How do we eliminate the probability of making a Type II error?
By saying "fail to reject" or "do not reject H0" instead of "accept"
100
What is the point estimator for averages
x(bar)
100
if b1<0, what kind of relationship do x and y have?
They have a negative linear relationship
200
What is a Type I error?
Rejecting H0 when it is true
200
What changes if standard deviation is unknown?
Use t instead of z, and use s instead of sigma
200
What do b1 and b0 represent in the linear regression equation?
b1 is the slope; b0 is the y-intercept
300
If alpha=0.05 and my p-value is 0.002, should I accept or reject the null?
Reject. 0.002<0.05, so we are inside the rejection region.
300
What is the confidence interval for p1-p2?
p1-p2 +/- z(alpha/2)*sqrt[(p1q1/n1)+(p2q2/n2)]
300
Write an equation describing the relationship between SST, SSR, and SSE.
SST=SSR+SSE
400
Write and label H0 and Ha for left-tailed, right-tailed, and two-tailed tests.
Left = less than in H0 // Right = greater than // Two = not equal to
400
When do you use a pooled estimator and what is the formula?
when p1=p2; p(bar)=(n1p1+n2p2)/(n1+n2)
400
How do you find r(xy) and s?
r(xy)=[sign of b1] sqrt(r^2), where r^2=SSR/SST ; s=sqrt(MSE)
500
For a Christmas and New Year’s week, the National Safety Council estimated that 500 people would be killed and 25,000 injured on the nation’s roads. The NSC claimed that 50% of the accidents would be caused by drunk driving. A sample of 120 accidents showed that 67 were caused by drunk driving. Use these data to test the NSC’s claim with a = .05. (Hint: sigma(p-bar)=.045644)
z=1.28, p-val=0.2006, 0.2006>0.05 so do not reject
500
Find a 95% confidence interval if p1=.48, p2=.40, n1=250, n2=150; if H0: p1=p2, should we reject?
(-0.02,0.18); cannot reject because 0 is in the interval
500
How do you calculate MSE?
SSE/(n-2)
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