# jeepers

#### hilarysears77

##### New Member
okay I have some problems that i am going to try my best to let you see what work I did. Le me know if I am right or where I went wrong and then I will fix it

A contractor desires to build new homes with fireplaces. He read that 80% of all home buyers want a fireplace. To test his claim he selected a sample of 30 homes and found that 20 wanted a fireplace. Use alpha = .02 to test his claim. Use the p-value method.

ho=p</U].80hi=>.80
P (hat)=20/30=.67
z= (.67)-(.80)
_____________
square root of (.67)(.33)
____________________
30

i got 1.52
and cv= .4357
(.5-.4357)=.0643>.02
do not accept the null

2nd ?
what is the equation for the regression line if n=7, sum of x=69, sum of y=528, sum of xy=4754, and sum of x squared =825

I got y1=106.089 + 290.679x

3rd ?

a study was conducted to determine if there was a relationship between the prices of a non-member of a club paid for various publications and the prices that a member paid for the same publications. Find the value of sum of x squared
x= 58, 42, 46, 32, 25, 75, 35, 63
___________________________
y= 32, 22, 20, 16, 19, 58, 34, 48

i got the sum of x squared is 19712
do i need to go further with this, because that is all it asked for,

let me know
hilary

#### JohnM

##### TS Contributor
The third one looks good.

On the second one, re-check your math. The slope should be -3.11

On the first one,

Ho: P <= 0.8
Ha: P > 0.8

z = (p - P)/sp

where p = .67, P = 0.8, and sp = sqrt(P*(1-P)/n) = sqrt(.8*.2/30) = .073

then z = (.67 - .80) / .073 = -1.781

the probability of z = -1.781 (or lower) is .037, which is larger than .02 (the critical value for .02 is z= -2.054), so we fail to reject Ho