5.5. For an n-period binomial tree, let Nu be the number of security price upticks from time to to fa. Explain why Nu is a binomial random variable. What are its expected value and variance if the tree has 40 steps and the uptick probability is 60%? 5.5. For an n-period binomial tree, let Nu be the number of security price upticks from time to to fa. Explain why Nu is a binomial random variable. What are its expected value and variance if the tree has 40 steps and the uptick probability is 60%