Which of the following events are equal? (a) A = {1,3}; (b) B = {x | x is a number on a die }; (c) C = {x | x2 4x +3=0 }; (d) D = {x | x is the number of heads when six coins are tossed}.

Section - 9.3 Comparison of Two population Means: Paired (Dependent) Samples Con▯dence Intervals for the di▯erence between Two Means: Paired Samples ▯ ▯ d ▯ t pd ▯=2 n where there are n pairs, d is the mean add s the standard deviation of their di▯erences....