find probability

Online A national retailer has tracked customers who visit its website and determined that 37% will make a purchase from the website within six months of their first website visit. Eight people who visit the website are selected at random as a sample. a. Determine the expected number in the sample who will make a purchase within six months. b. Calculate the standard deviation in the number who will make a purchase. . Sketch the PDF and describe its shape. d. Calculate the probability of 2 or fewer making a purchase within six months. ***Normal Distribution. Note on some formulas for normal distribution: P(X x) =1-P(X S x) =1-CDF(x) P(a s X S b) = CDF(b) - CDF(a) Objective If X = N(H, o), Excel If X = N(0,1), Excel PDF f (x) NORM. DIST(x, H, 6, 0) NORM. S. DIST(x, 0) CDF F(x) = P(X x) 1 - NORM. DIST(x, H, 6, 1) 1 - NORM. S. DIST(x, 1) P(asXS b) NORM. DIST(b, H, o, 1) NORM. S. DIST(b, 1) - NORM. DIST(a, H, o, 1) - NORM. S. DIST(a, 1) Find m, such that P(X S m) = NORM. INV(m, /, o) NORM. S. INV(m) 0.1