Let X denote the number of dad jokes Albert makes in one day. Suppose X has the following probability distribution: x f(x) 0 0.1 1 0.2 2 0.2 3 0.3 4 0.2 a) Find the probability that Albert will tell at least 2 dad jokes in a day. b) Find the expected number of times Albert will tell a dad joke in a day, E[X]. c) Find the standard deviation of dad jokes told in a day, sd[X].

a) 0.7

b) 2.3

c) 1.2689

Step-by-step explanation:

a) Find the probability that Albert will tell at least 2 dad jokes in a day.

P(X ≥ 2) = P(X=2)+P(X=3)+P(X=4) = 0.2+0.3+0.2 = 0.7

b) Find the expected number of times Albert will tell a dad joke in a day, E[X].

E[X] = 0*P(X=0)+1*P(X=1)+2*P(X=2)+3*P(X=3)+4*P(X=4) =

= 0.2+2*0.2+3*0.3+4*0.2 = 2.3

c) Find the standard deviation of dad jokes told in a day.

The standard deviation can be defined as

On one hand we have

on the other hand,

So  

you never say the total so we cant find the percentage used for petrol

step-by-step explanation:

175

step-by-step explanation:

2 inches x 10 miles = 200 miles - 3 inches = 175