From two normal populations assumed to have the same variance, independent ran-dom samples of sizes 15 and 19 were drawn. The first sample (with n1 5 15) yielded mean and standard deviation 111.6 and 9.5, respectively, while the second sample (n2 5 19) gave mean and standard deviation 100.9 and 11.5, respectively. The esti-mated standard error of the difference in sample means is .

In the following diagram it is given that dec, ab || dc, ad || eb, and ad is congruent to bc. a)why isn't abc a parallelogram even though it has a pair of parallel sides and a pair of congruent sides b)explain why be must be congruent to bc. further explain what type of triangle this makes triangle abc and what it tells you about angle 1 and angle 2c) finally why must angle 3 be congruent to angle 1? further, explain why we know that angle 3 is congruent to angle 2