0 Question 4 81 pt '0 1 @Detail: How many different ways are there to select a group of 7 out of 8 people ? E Question Help: 8 Message instructor 0 Question 5 E4 1 pt '0 1 G Details One of the reasons why the concept of an unfair coin is important in probability is that many real-life experiments can be modeled by a toss of an unfair coin. For example, if the probability of the price of the stock moving up during a day is 0.5, then observing the daily movements of the price of the stock can be modeled by a toss of an unfair coin for which Heads is associated with Up and Tails with DOWn. Thus, the probability of the price of the stock moving up 5 days out of 8 days is exactly the same as the probability of getting 5 heads from tossing the coin 8 times and can be computed using the following formula P(kH) = Cfpkll :DYH\" withn= 8,k= 5, andp = 0.5: P(5H/8) = C53 - 0.55 ~ 0.53 2 56- 0.03125 - 0.125 = 0.2188 Find the probability of the price of the stock moving up 4 days out of 9 days: (Round the answer to 4 decimal places.) Question Help: 8 Message instructor