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spayn [35]
3 years ago
6

For a discrete random variable that takes a value of 8 with probability .75 and a value of -4 with probability of .25, what is t

he expected value and what is the variance
Mathematics
1 answer:
klasskru [66]3 years ago
5 0

Answer:

5.20

Step-by-step explanation:

X : ______ 8 ____ - 4

P(X) : ___ 0.75 __ 0.25

The expected mean E(x) :

E(x) = ΣX / n

n = sample size = 2

E(x) = (8*0.75) + (-4*0.25)

E(x) = 6 - 1

E(x) = 5

The standard deviation : sqrt(Var(x))

Var(x) = Σx²p(x) - E(x)²

Var(x) = (8^2 * 0.75) + (-4^2 * 0.25)) - 5^2

Var(x) = ((64 * 0.75) + (16* 0.25)) - 25

Var(x) = (48 + 4) - 25

Var(X) = 27

Standard deviation = sqrt(27)

Standard deviation (x) = 5.1961524

Standard deviation = 5.20

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Answer:

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Step-by-step explanation:

x is the number of sales made during the week

5 0
2 years ago
Edward Winslow deposited $20,000.00 into a savings account paying 6% annual interest compounded monthly. What amount will be in
Ad libitum [116K]

Answer:

$28360

Step-by-step explanation:

Step one:

Given data

P=20000

rate= 6%

time= 6years

Step two:

compound interest

A=P(1+r)^t

substitute

A=20000(1+0.06)^6

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4 0
2 years ago
What is the length of s?​
Serggg [28]

Answer:

10

Step-by-step explanation:

We will use trigonometry to solve this problem.

We see that the side provided is the hypotenuse and the side we are looking for is opposite to the angle provided. Thus, we will use sin since sin uses opposite/hypotenuse.

Now we solve.

sin45 = x/14

sin45 * 14 = x

x = 9.899494936611665

6 0
3 years ago
If the length of segment RQ is 8, what is the length of segment PQ?
artcher [175]
Half of 8 is 4 so it’s b
7 0
3 years ago
What fraction is equal to 1/5? 4/7 , 6/30 , 5/15
Zolol [24]
There are a lot of fraction that can be equal to the values given above. It can be as follows:

<span>1/5 = 2/10, 3/15, 4/20, 5/25, 6/30, 7/35, 8/40
 
4/7 = 8/14, 12/21, 16/28 
 
6/30 = 12/60, 18/90, 24/120

5/15 = 1/3 , 10/30, 20/60 

Hope this helps. Have a nice day.</span>
6 0
3 years ago
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