Kellp me answerquestion 1

In the game of roulette, a wheel consists of 38 slots numbered 0, 00, 1, 2,..., 36. To play the game, a metal ball is spun a

Oxana [17]

Answer:

$E(X)=-0.0526$

$Sd(X)=5.763$

Step-by-step explanation:

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.

Let X be a random variable which denotes the money you may win or lose on each spin.

In the game of roulette, a wheel consists of 38 slots. To play the game, a metal ball is spun around the wheel and is allowed to fall into one of the numbered slots. If the number of the slot the ball falls into matches the number you selected, we win $35; otherwise we lose $1. So we have just one possibility to win and 37 of lose on an individual game.

___________________________

X P(X)

___________________________

35 1/38

-1 37/38

___________________________

In order to calculate the expected value we can use the following formula:

$E(X)=\sum_{i=1}^n X_i P(X_i)$

And if we use the values obtained we got:

$E(X)=(35)*(\frac{1}{38})+(-1)(\frac{37}{38})=-0.0526$

In order to find the standard deviation we need to find first the second moment, given by :

$E(X^2)=\sum_{i=1}^n X^2_i P(X_i)$

And using the formula we got:

$E(X^2)=(35^2)*(\frac{1}{38})+((-1)^2)(\frac{37}{38})=33.211$

Then we can find the variance with the following formula:

$Var(X)=E(X^2)-[E(X)]^2 =33.211-(-0.0526)^2 =33.208$

And then the standard deviation would be given by:

$Sd(X)=\sqrt{Var(X)}=\sqrt{33.208}=5.763$

4 0

2 years ago

8. Given: PQR and TSR are right triangles,

rewona [7]

Answer:

The answer is below

Step-by-step explanation:

A triangle is a polygon with three sides and three angles. Types of triangles are scalene, right angled, isosceles, equilateral.

A right angled triangle is a triangle with one angle equals to 90°.

Statement Reason

∠PQR = ∠RST Given. ∠PQR = ∠RST = 90° (definition for right

angle triangle.

PQ = ST Given

PR ≅ RT Since R is the midpoint of PT, hence PR = RT

ΔPQR ≅ ΔTSR Side-angle-side triangle congruence theorem.

the Side-angle-side triangle congruence theorem

states that if two sides and an included angle of

one triangle is equal to two sides and an included

angle of another triangle, then the two triangles

are congruent. PQ=ST, PR = RT and ∠PQR = ∠TSR

3 0

2 years ago

Solve for x:x-7=-20<br>1)13<br>2)27<br>3)-13<br>4)-3

Marianna [84]

3.)-13

x-7= -20

x = -20+7

x= -13

4 0

2 years ago

Read 2 more answers

Hello, I'm new! I need help

melamori03 [73]

The interest in the first month is given as $ 97.1. The principal balance in the second question is $15,030.02

<h3>How to solve for the interest in the first month</h3>

1. We have to solve for the cost of the car

This would be = 19,725*(1.0475)

= 20,661.9375

There is a Down payment = 2,175

balance would be 20661.9375-2,175 = 18,486.94

average rating interest of new car = 6.30%

So the interest accrued in first month = 18,486.94x0.063/12 = $ 97.1

2. cost = 15867

sales tax = 5.25%

10 percent down payment

5.25/100 = 0.0525

cost of car = 15867 + (15867 * 0.0525)

= 16700 dollars

10% of 16700 dollars

= 1670 dollars

principal balance = 16700 - 1670

= $15,030.02