# Need my answers checked.. Am I right? Fingers crossed : )

#### crunchy

##### New Member
Hey everyone,
tomororw morning I am doing a statisctics exam but I had a few questions before I go in there. I have been reviewing the slides from my most recent classes and was confused about how to go about figuring out this question.
I remember that the prof mentioned it in class but I for some reason did not take notes.. silly me.

The prof used a working paper as an example during class..

Authors Matthews et al. examined time series data on violence and real (i.e., inflation-adjusted) price of beer from 1995 to 2000 (“Violence-related injury and the price of beer in England and Wales”, Cardiff Economics Working Papers, Jan. 2006). The authors collected data for 10 regions over 60 months (5/1995 to 4/2000), for a total of 600 observations. They performed a multiple regression and obtained the following equation (with standard errors reported underneath each coefficient):
The (unadjusted) R2 for the model was 0.1966.

violence =
7.73 –0.44IA –0.19 ISpr– 0.05 IW+0.036 IS– 1.31 PB– 0.23 PH– 0.028 U
(1.42)(0.0065)(0.0067) (0.0065) (0.011)(0.295) (0.041)(0.004)(0.004)

where
IA(autumn), ISpr(ing), and IW(inter) are indicator variables
IS(port) is an indicator variable for “major sporting event”
PB(eer) and PH(ouse) are the inflation-adjusted prices of beer and housing, respectively, in pounds
U is youth unemployment
E is ethnic density

What is a 99% confidence interval for the slope for PBeer? Show your work. What does this mean? Can you put words to the numbers?

My Answer : The confidence interval is telling me that 99% of the time, the slope of the regreassion line will be the change in violence-realted injury and the prce of beer in England and Whales.

BUT

How do I construct the confidence interval?

I cannot remember how to do it correctly..
oh no.

Also the change can be caused buy something else right?
The number is statistically significant, but it still does not mean that beer prices and violence are realted. Maybe the violence could b elinked to something else? Weather?

I would love any input,

thanks!