STAB57H3 Lecture 1:

Considere o seguinte conjunto de dados: 134 – 114 – 103 – 103 – 151. Em relação à média (x), a mediana (Md) e a moda (Mo), assinale a alternativa correta: 

a) Md < x < Mo

b) Mo < x < Md

c) x < Md < Mo

d) Mo < Md < x

e) Md < Mo < x

2. Let A = 1 21 . Consider the following elementary matrices, E = (1 0 0 -7 (1 ) and E3 = ( 6 1 ), E = ( ). Which one of the following is true? A) A = E1 E3 E, E4 B) A = E1 E2 E3 C) A = E3EE2 D) A = E2E E E) None of the above.

Let the random variable X have the pmf f(x) = (│x│+ 1)²/9, x = -1, 0, 1. Compute E(X), E(X²), and E(3X² - 2X + 4).