(b) Out of 10,000 students enrolled in BEEE, 10 students are at least 21 years old and above. Suppose that the age of BEEE students are independent Gaussian variables with an expected value 20.5 years old. Find the following: Calculate Ox, the standard deviation of the age of BEEE students. [3 Marks] (11) What is the probability that a randomly chosen student is at least 21.2 years old? [3 Marks] (a) TCP protocol works in a way that when a sender sends a message, the protocol attempts to transmit the message by setting up a connection. The sender will then wait for an acknowledgement from the receiver. If none arrives within 0.2 s, it will try for 3 times. After 3 tries, the protocol will stop trying and will generate a delivery failure message. Probability of getting an acknowledgement is p. (b) (1) Draw the tree diagram to represent the above scenario. [3 Marks] (ii) Given the probability that a message is delivered to receiver successfully to be 0.7, what is the PMF of B, the number of messages transmitted in an attempt? Assume all transmissions are independent. [5 Marks] (111) What is the probability that the TCP will generate a delivery failure message? [2 Marks] Out of 10,000 students enrolled in BEEE, 10 students are at least 21 years old and above. Suppose that the age of BEEE students are independent Gaussian variables with an expected value 20.5 years old. Find the following: Calculate σy, the standard deviation of the age of BEEE students. [3 Marks] (ii) What is the probability that a randomly chosen student is at least 21.2 years old? [3 Marks]