All categories

2 years ago

Katherine v

Mathematics

1 answer:

maks197457 [2]2 years ago

6 0

Answer:

13/102

Step-by-step explanation:

In a standard deck of 52 cards, there are 13 black spades, 13 black clubs, 13 red diamonds and 13 red hearts. There are 26 black cards in the deck of 52 cards.

Probability of drawing a black card = 26/52 = 1/2

Suppose we drew the black card. There are now only 51 cards left in the deck. ALL of the hearts are still there - 13 of them.

Probability of drawing a heart from this deck of 51 = 13/51

In general, for the probability of event A and then event B, we multiply.

1/2 x 13/51 = 13/102

You might be interested in

What is x? This is due by midnight

Alexxx [7]

What are all ur answers

4 0

3 years ago

Read 2 more answers

Suppose that a college determines the following distribution for X = number of courses taken by a full-time student this semeste

lidiya [134]

Answer:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 3*0.07 +4*0.4 +5*0.25 +6*0.28= 4.74$ In order to find the variance we need to calculate first the second moment given by:

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 3^2*0.07 +4^2*0.4 +5^2*0.25 +6^2*0.28= 23.36$ And the variance is given by:

$Var(X) = E(X^2) +[E(X)]^2 = 23.36 -[4.74]^2 = 0.8924$

And the deviation would be:

$Sd(X) =\sqrt{0.8924} =0.9447$

Step-by-step explanation:

Previous concepts

The expected value of a random variable X is the n-th moment about zero of a probability density function f(x) if X is continuous, or the weighted average for a discrete probability distribution, if X is discrete.

The variance of a random variable X represent the spread of the possible values of the variable. The variance of X is written as Var(X).

Solution to the problem

For this case we have the following distribution given:

X 3 4 5 6

P(X) 0.07 0.4 0.25 0.28

We can calculate the mean with the following formula:

$E(X) = \sum_{i=1}^n X_i P(X_i) = 3*0.07 +4*0.4 +5*0.25 +6*0.28= 4.74$

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

$E(X^2) = \sum_{i=1}^n X^2_i P(X_i) = 3^2*0.07 +4^2*0.4 +5^2*0.25 +6^2*0.28= 23.36$

And the variance is given by:

$Var(X) = E(X^2) +[E(X)]^2 = 23.36 -[4.74]^2 = 0.8924$

And the deviation would be:

$Sd(X) =\sqrt{0.8924} =0.9447$

3 0

3 years ago

Which angles are correspoding angles

Luden [163]

Answer:

When two lines are crossed by another line (which is called the Transversal), the angles in matching corners are called corresponding angles. Example: a and e are corresponding angles. When the two lines are parallel Corresponding Angles are equal.

7 0

2 years ago

I need help with this please

Harlamova29_29 [7]

-12y+14-9y=14
-21y=0
y=0, x=7

3 0

3 years ago

Which of the following are steps to use when formulating all that apply equation? Check an A. Write each fact as a variable expr

kramer

Answer:

Step-by-step explanation:

6 0

3 years ago

Read 2 more answers