Statistic question

Question 10] Conducting a Hypothesis Test to Compare the Difference Between Two Means, (Dependent Samples), variance unknown. The number of matched-pair differences (DF) is - to; al n1+ n2-2 bj n-1 cl na nlen2-1 none of the above Question 11) The Mortgage Bankers Association would like to estimate the proportion of delinquent mortgages in the state of Alabama, A pilot sample of 50 mortgages from Alabama found that seven were delinquent, Determine the total sample size needed to construct a 904% confidence interval for the proportion of delinquent mortgages in Alabama with a margin of error equal to 49%