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Mathematics

1 answer:

Ivahew [28]3 years ago

3 0

$\sum_{k=4}^8(2k+2)=2\cdot4+2+2\cdot5+2+2\cdot6+2+2\cdot7+2+2\cdot8+2\\
\sum_{k=4}^8(2k+2)=10+12+14+16+18\\
\sum_{k=4}^8(2k+2)=70$

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Antonio uses dish soap in his recipe for giant bubbles. he compares the prices of two brands of soap. which brand is the better

schepotkina [342]

Answer:$2.36

Step-by-step explanation:

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3 years ago

WORTH 100 POINTS WILL PICK BRAINLYLIST Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used.

Yanka [14]

Answer:

1, 1/2, 3/2

Step-by-step explanation:

This is a prism (a 3d rectangle) and so your formula for finding the volume is V= L x W x H.

For the prism:

L= 1 (4 cubes x 1/4 = 4)

W = 1/2 (2 cubes x 1/4 = 1/2)

H = 3/2 (6 cubes x 1/4 = 6/4 = 3/2)

That's your answer, the tile 1, 1/2, 3/2

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The weight of an adult swan is normally distributed with a mean of 26 pounds and a standard deviation of 7.2 pounds. A farmer ra

Snezhnost [94]

Let $X$ denote the random variable for the weight of a swan. Then each swan in the sample of 36 selected by the farmer can be assigned a weight denoted by $X_1,\ldots,X_{36}$ , each independently and identically distributed with distribution $X_i\sim\mathcal N(26,7.2)$ .

You want to find

$\mathbb P(X_1+\cdots+X_{36}>1000)=\mathbb P\left(\displaystyle\sum_{i=1}^{36}X_i>1000\right)$

Note that the left side is 36 times the average of the weights of the swans in the sample, i.e. the probability above is equivalent to

$\mathbb P\left(36\displaystyle\sum_{i=1}^{36}\frac{X_i}{36}>1000\right)=\mathbb P\left(\overline X>\dfrac{1000}{36}\right)$

Recall that if $X\sim\mathcal N(\mu,\sigma)$ , then the sampling distribution $\overline X=\displaystyle\sum_{i=1}^n\frac{X_i}n\sim\mathcal N\left(\mu,\dfrac\sigma{\sqrt n}\right)$ with $n$ being the size of the sample.

Transforming to the standard normal distribution, you have

$Z=\dfrac{\overline X-\mu_{\overline X}}{\sigma_{\overline X}}=\sqrt n\dfrac{\overline X-\mu}{\sigma}$

so that in this case,

$Z=6\dfrac{\overline X-26}{7.2}$

and the probability is equivalent to

$\mathbb P\left(\overline X>\dfrac{1000}{36}\right)=\mathbb P\left(6\dfrac{\overline X-26}{7.2}>6\dfrac{\frac{1000}{36}-26}{7.2}\right)$
$=\mathbb P(Z>1.481)\approx0.0693$