Hi Binomial Distribution: p(do not get enough sleep) = .9 Using TI or similarly an inexpensive calculator like a Casio fx-115 ES plus n = 28 ... P(x = 26) = binompdf(28, .9, 26) = .2442 ... P(x > 26) = 1- P(x ≤ 26)= 1 - binomcdf(28, .9, 26) = 1-.7848 = .2152 Important You are comfortable using Your Calculator. Wish You the Best in your Studies.