Question

If X denotes the number of heads in a single toss of 4 fair coins, find (a) P(X 3), (b) P(X<2). (c) P( X2), (d) P(1 < x≤ 3).​

Answer 1

Answer:

Step-by-step explanation:

f X is a discrete random variable then its range RX is a countable set, so, we can list the elements in RX. In other words, we can write

RX={x1,x2,x3,...}.

Note that here x1,x2,x3,... are possible values of the random variable X. While random variables are usually denoted by capital letters, to represent the numbers in the range we usually use lowercase letters such as x, x1, y, z, etc. For a discrete random variable X, we are interested in knowing the probabilities of X=xk. Note that here, the event A={X=xk} is defined as the set of outcomes s in the sample space S for which the corresponding value of X is equal to xk. In particular,