The National Center for Education would like to estimate the average student debt for the class of 2010 for the state of Ohio with a 90% confidence interval and a margin of error within plus or minus $1,500. Assuming the standard deviation for student debt in this state is $9,000, the required sample size is .

i think it is everything has to equal 180 so, if i correct 4=c. 6=d. 8=a. 7=b. and the last question would be c. because they are parallel lines and they are congruent.

step-by-step explanation:

the reason everything has to equal to 180 is because that is how it works. i'm guessing that is its rule. 4 and 8 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 6 and 7 are congruent and parallel so, that would be 30+30 because they have the same number. it would equal 60. 60+60 is 180. so, now you have your answer

is this part of a question or something