When circuit boards used in the manufacture of compact disc players are tested, the long-run percentage of defectives is 10%. Let X = the number of defective boards in a random sample of size n = 20,...

Could you help me with the last two questions? thanks!

Extracted text: When circuit boards used in the manufacture of compact disc players are tested, the long-run percentage of defectives is 10%. Let X = the number of defective boards in a random sample of size n = 20, so X - Bin(20, 0.10). (a) Determine P(X < 2).="" 0.677="" (b)="" determine="" p(x="" 2="" 5).="" 0.0431="" (c)="" determine="" p(1="" sxs="" 4).="" 0.8345="" (d)="" what="" is="" the="" probability="" that="" none="" of="" the="" 20="" boards="" is="" defective?="" (e)="" calculate="" the="" expected="" value="" and="" standard="" deviation="" of="" x.="" e(x)="Ox">