Answer:
The random variable (number of toppings ordered on a large pizza) has a mean of 1.14 and a standard deviation of 1.04.
Step-by-step explanation:
<em>The question is incomplete:</em>
<em>The probability distribution is:</em>
<em>x P(x)
</em>
<em>
0 0.30
</em>
<em>1 0.40
</em>
<em>2 0.20
</em>
<em>3 0.06
</em>
<em>4 0.04</em>
The mean can be calculated as:

(pi is the probability of each class, Xi is the number of topping in each class)
The standard deviation is calculated as:

Answer:
172
Step-by-step explanation:
42+1= 43
43 x 4= 172
Answer:
Wilma has $12.
Step-by-step explanation:
Since we don't know how many hours she worked, we know that Wilma earned 9x dollars at her job. Then she spends $15, so we can just subtract 15 from 9x.

We can just replace the x with 3 to get:

Hence, Wilma has $12.
Answer:
-3
Step-by-step explanation:
this is x equals to -3
we can divide the 4 to other side
Consider, please, this solution/explanation:
1. suppose, that number of cars is 'x', numbers of buses is 'y'.
2. according to the condition 'a total of 32', it means that x+y=32. This is the 1st equation.
3. according to the condition in one car are 3x persons, in one bus are 27y persons, and totaly 3x+27y=408 people. This is the 2d equation.
4. if to solve the system of two equations:

Answer: 13 - b., 19 - c.