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3 years ago

GONNA UPVOTE

Mathematics

1 answer:

Artyom0805 [142]3 years ago

3 0

$\dfrac{7\times90+11\times82}{18}\approx85.1$

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xP(x)00.2510.0520.1530.55Find the standard deviation of this probability distribution. Give your answer to at least 2 decimal pl

Nookie1986 [14]

The Solution:

Given:

Required:

Find the standard deviation of the probability distribution.

Step 1:

Find the expected value of the probability distribution.

$E(x)=\mu=\sum_{i\mathop{=}0}^3x_iP_(x_i)$ $\begin{gathered} \mu=(0\times0.25)+(1\times0.05)+(2\times0.15)+(3\times0.55) \\ \\ \mu=0+0.05+0.30+1.65=2.0 \end{gathered}$

Step 2:

Find the standard deviation.

$Standard\text{ Deviation}=\sqrt{\sum_{i\mathop{=}0}^3(x_i-\mu)^2P_(x_i)}$ $=(0-2)^2(0.25)+(1-2)^2(0.05)+(2-2)^2(0.15)+(3-2)^2(0.55)$ $=4(0.25)+1(0.05)+0(0.15)+1(0.55)$ $=1+0.05+0+0.55=1.60$

Thus, the standard deviation is 1.60

Answer:

1.60

8 0

2 years ago

Ann's rent increased from $1,200 to $1,350 By what percent did her rent increase

Ierofanga [76]

Answer:

1% of 1200 is 12, so to find this we multiply 12 until we get 150

150/12 = 12.5

12.5%

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3 years ago

In the triangle below, what is the length of EF A. 6 B. 24 C. 12 D. 25

Ymorist [56]

Answer:

Step-by-step explanation:

since DE and EF are congruent then we now know that EF is also 12

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3 years ago

If the sample size is multiplied by 4, what happens to the standard deviation of the distribution of sample means?

Feliz [49]

Increasing the sample size by a factor of 4 or multiplying it by 4 is equal to increasing the standard error by 1/2. Therefore, the interval will be half as varied. This also works almost for population averages as lengthy as the multiplier from the t-curve doesn't modify much when increasing the sample size.

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4 years ago

30 points! You start at (-2, 2). You move left 3 units and right 10 units. Where do you end?

Cerrena [4.2K]

Answer:

The answer is (5, 2)

Step-by-step explanation:

I. If move left = -x

move right = +x

So -2 - 3 = -5 => move left

-5 + 10 = 5 => move right

I suggest that move left and right is x cordinate

The answer is (5,2)

Is that correct?

7 0

3 years ago