That would be 7 because 7x2=14 and 14-9=5
E=Z*sqrt (p(1-p)/N), where E= error margin, p=proportion, N=sample size
Katrina's margin error at 85% confidence interval: E=1.96*sqrt (p(1-p)/100) = 0.196 sqrt (1(1-p))
Mathew's margin error at 99% confidence interval: E= 2.58*sqrt (p(1-p)/400) = 0.129 sqrt (p(1-p))
Since both obtained same estimate of proportion (that is, value of p), it can be seen that Mathew's estimate will have a small error (That is, 0.129 is smaller than 0.196). This can be attributed to larger sample size although a wider confidence (99%) interval was considered.
x = 10
since GI bisects ∠DGH then ∠DGI = ∠IGH, hence
2x - 13 = x - 3 ( subtract x from both sides )
x - 13 = - 3 ( add 13 to both sides )
x = 10
A (-5, 6)
B (-5, 2)
C (-9, 2)
D (-9, 6)
As it is just a rotation around the origin by 180, you can just change the sign in front of the numbers :)
