3 and 3/4lb=20.25
what you should do is divide both sides by 3 and 3/4 but that isnt nice

convert 3 and 3/4 to improper
3 and 3/4=3+3/4=12/4+3/4=15/4
15/4lb=20.25
times 4/15 to both sides (15/4 times 4/15=60/60=1)
1lb=81/15
1lb=5.4

answer is
1lb=$5.40

5 0

3 years ago

Suppose that the probabilities of a customer purchasing 0, 1, or 2 books at a book store are 0.20.2, 0.30.3, and 0.50.5, res

PIT_PIT [208]

Answer:

0.78

Step-by-step explanation:

We have the next probability distribution:

X P(X)

0 0.2

1 0.3

2 0.5

As we can see when we add all the probabilites the result is 1. Now calculating the mean we have:

$mean=\mu=(0\times0.2)+(1\times 0.3)+(2\times 0.5)=0+0.3+1=1.3$

The standard deviation is:

$\sigma=\sqrt{\sum(x-\mu)^{2}(P(x))}$

Then using the data that we have:

$\sigma=\sqrt{\sum(x-\mu)^{2}(P(x))}\\\sigma=\sqrt{(0-1.3)^{2}(0.2)+(1-1.3)^{2}(0.3)+(2-1.3)^{2}(0.5)}\\\\\sigma=\sqrt{(-1.3)^{2}(0.2)+(-0.3)^{2}(0.3)+(0.7)^{2}(0.5)}\\\\\sigma=\sqrt{(1.69)(0.2)+(0.09)(0.3)+(0.49)(0.5)}\\\\\sigma=\sqrt{0.338+0.027+0.245}\\\\\sigma=\sqrt{0.61}\\\\\sigma=0.78\\$

Then the standard deviation is 0.78

6 0

3 years ago