# R Exercise 1. (a) Simulate the

R Exercise 1. (a) Simulate the rolling of two dice 10,000 times.(b) Identify which rolls of the dice are in the event A, the diceadd up to a perfect square (4 or 9). Determine what proportion ofthe 10,000 rolls are in A. (c) Identify which rolls of the dice arein the event B, the dice add up to an even number. Determine whatproportion of the 10,000 rolls are in B. (d) Find out which rollsare in A ∩ B. Find the proportion that are in A ∩ B. How does thatcompare to the proportion in A multiplied by the proportion thatare in B? (e) Of the rolls in which B occurs that you identified inpart (c), what proportion of those rolls are also in A. How doesthis compare to the proportion you computed in part (b)? (f) Doyour results in this R exercise match what you would expect basedon the answers you got in problem (4) of the previous sectio

Answer:

(a)

Simulate the rolling of two dice 10,000 times D1 and D2 are the10,000 results of roll of dice 1 and dice 2.

**D1 = sample(c(1:6), 10000, replace = TRUE)D2 = sample(c(1:6), 10000, replace = TRUE)**

**Sum = D1 + D2**

(b)

The event A, the dice add up to a perfect square (4 or 9).

**A = Sum[Sum == 4 | Sum ==9]**

Proportion of A, P(A) = 0.189

**length(A) / length(Sum)**

(c)

The event B, the dice add up to an even number.

**B = Sum[Sum %% 2 == 0]**

Proportion of B, P(B) = 0.5049

**length(B) / length(Sum)**

(d)

The rolls are in A ∩ B (common to both A and B)

> **intersect(A,B)**[1] 4

The proportion that are in A ∩ B is 0.0792

**length(Sum[Sum == 4]) / length(Sum)**

P(A) * P(B) = 0.189 * 0.5049 = 0.0954

The proportion in A multiplied by the proportion that are in Bis not equal to P(A ∩ B)

(e)

Of the rolls in which B occurs, the proportion of those rollsare also in A is 0.4190476

**length(Sum[Sum == 4]) / length(A)**

This proportion is greater than the P(A) calculated in part(b).