Ask question

Ask question

All categories

3 years ago

14

To calculate the area of a rectangle we multiply length by width the length of this rectangle below is 9 inches and the area is

36x-27y square inches what is the width of the rectangle

1 answer:

charle [14.2K]3 years ago

8 0

Answer:

547

Step-by-step explanation:

You might be interested in

Please help for 18 n 19

Hitman42 [59]

$18. \ \ \frac{-1}{x-9}- \frac{-2}{x+7}= \frac{-1(x+7)+2(x-9)}{(x-9)(x+7)}= \frac{-x-7+2x-18}{(x-9)(x+7)}= \frac{x-25}{(x-9)(x+7)}$

$\frac{2}{x}+ \frac{12}{x}=7 \\ \\ \frac{14}{x} =7 \\ \\ x= \frac{14}{7} \\ \\ x=2$

7 0

3 years ago

Write 25/22 as a decimal and round it to the nearest hundredth

MrRissso [65]

Answer: 1.14

Step-by-step explanation:

25/22 = 1.1363

7 0

3 years ago

Y+y+y+3y<br>please help me

Amanda [17]

Answer: 6y I think. If you would have to add all of the y’s and so you would have 3 y’s and then you add both 3 y’s so 6y

I don’t know if I am right sorry if I’m wrong

4 0

3 years ago

What is a prime and composite number?

Aloiza [94]

A Prime Number is a number that you can only get by multiplying it by itself and 1.

A Composite Number is a number that has more than one way to get the the solution.

Examples:

Prime: 17. only way to get it is 1×17

Composite: 15. 1×15 obviously. also 3×5

4 0

4 years ago

Read 2 more answers

Kelsie works at a bicycle shop as a salesperson. She records the number of bicycles she sells daily. Here is the probability dis

Andru [333]

Answer:

a) $E(B)= \sum_{i=1}^n B_i P(B_i) =0*0.3+1*0.5+2*0.15+ 3*0.05=0.95$

b) $E(T)= \sum_{i=1}^n T_i P(T_i) =10*0.3+20*0.5+30*0.15+ 40*0.05=19.5$

c) $E(B^2)= \sum_{i=1}^n B^2_i P(B_i) =0^2 *0.3+1^2 *0.5+2^2 *0.15+ 3^2 *0.05=1.55$

And the variance is given by:

$Var(B) = E(B^2) -[E(B)]^2 = 1.55- [0.95]^2 =0.6475$

And the deviation would be $Sd(B) = \sqrt{0.6475}=0.8047$

$E(T^2)= \sum_{i=1}^n T^2_i P(T_i) =10^2 *0.3+20^2 *0.5+30^2 *0.15+ 40^2 *0.05=445$

And the variance is given by:

$Var(T) = E(T^2) -[E(T)]^2 = 445- [19.5]^2 =64.75$

And the deviation would be $Sd(T) = \sqrt{64.75}=8.047$

Step-by-step explanation:

Previous concepts

In statistics and probability analysis, the expected value "is calculated by multiplying each of the possible outcomes by the likelihood each outcome will occur and then summing all of those values".

The variance of a random variable Var(X) is the expected value of the squared deviation from the mean of X, E(X).

And the standard deviation of a random variable X is just the square root of the variance.

Solution to the problem

Part a

For this case we have the following info:

B 0 1 2 3

____________________________________

T 10 20 30 40

____________________________________

P 0.3 0.5 0.15 0.05

____________________________________

And we can calculate the expected value for the random variable B like this:

$E(B)= \sum_{i=1}^n B_i P(B_i) =0*0.3+1*0.5+2*0.15+ 3*0.05=0.95$

Part b

Similar to part a we can find the expected value for the random variable T like this:

$E(T)= \sum_{i=1}^n T_i P(T_i) =10*0.3+20*0.5+30*0.15+ 40*0.05=19.5$

Part c

In order to find the variance for B we need to calculate the second moment given by:

$E(B^2)= \sum_{i=1}^n B^2_i P(B_i) =0^2 *0.3+1^2 *0.5+2^2 *0.15+ 3^2 *0.05=1.55$

And the variance is given by:

$Var(B) = E(B^2) -[E(B)]^2 = 1.55- [0.95]^2 =0.6475$

And the deviation would be $Sd(B) = \sqrt{0.6475}=0.8047$

Similar for the random variable T we have:

$E(T^2)= \sum_{i=1}^n T^2_i P(T_i) =10^2 *0.3+20^2 *0.5+30^2 *0.15+ 40^2 *0.05=445$

And the variance is given by:

$Var(T) = E(T^2) -[E(T)]^2 = 445- [19.5]^2 =64.75$

And the deviation would be $Sd(B) = \sqrt{64.75}=8.047$

7 0

4 years ago