All categories

2 years ago

Select all shapes that have a volume of \small 36\pi cubic units.

Mathematics

1 answer:

Gnesinka [82]2 years ago

5 0

Answer:

Step-by-step explanation:

Chelsea is making a kite in the shape of a triangle. To determine if the triangle is a right triangle, Chelsea completed the following steps.

Step 1:

Find the side lengths of the triangle: 30 inches, 24 inches, 18 inches.

Step 2:

Substitute the values into the Pythagorean theorem: 18 squared + 24 squared = 30 squared.

Step 3:

Combine like terms: (18 + 24) squared = 30 squared.

Step 4:

Evaluate each side: 1764 not-equals 900.

Chelsea says the triangle is not a right triangle. Which best describes the accuracy of her explanation?

The triangle is actually a right triangle. In step 2, Chelsea incorrectly substituted the values into the Pythagorean theorem.

The triangle is not a right triangle, but in step 2 Chelsea incorrectly substituted the values into the Pythagorean theorem.

The triangle is actually a right triangle. In step 3, Chelsea incorrectly rewrote the expression on the left side of the equation.

The triangle is not a right triangle, but in step 3, Chelsea incorrectly rewrote the expression on the left side of the equation.

You might be interested in

Find the value of x. The diagram is not to scale.

DiKsa [7]

Sum of interior angles in a pentagon=540°

148+112+2x+2x+10+90=540

360+4x=540

4x=540-360

4x=180

x=180/4

x=45°

5 0

2 years ago

The absolute value of 5 is -5 because -5 is the opposite of five. What is the error?

aksik [14]

The absolute value is |5| = -5

6 0

3 years ago

Please help me at this wit steps how did you did it

balu736 [363]

Answer:

5. LCM of 7 and 14: 14.

multiples of 7: 7, 14

multiples of 14: 14

LCM of 8 and 12: 24.

multiples of 8: 8, 16, 24

multiples of 12: 12, 24

Step-by-step explanation:

$.$

5 0

3 years ago

How many pounds is a quarter of a ton?

zmey [24]

$1 \ ton = 2000 \ lbs
\\2000 / 4 = 500
\\\boxed {500}$

3 0

3 years ago

Read 2 more answers

Let X1,X2......X7 denote a random sample from a population having mean μ and variance σ. Consider the following estimators of μ:

Viefleur [7K]

Answer:

a) In order to check if an estimator is unbiased we need to check this condition:

$E(\theta) = \mu$

And we can find the expected value of each estimator like this:

$E(\theta_1 ) = \frac{1}{7} E(X_1 +X_2 +... +X_7) = \frac{1}{7} [E(X_1) +E(X_2) +....+E(X_7)]= \frac{1}{7} 7\mu= \mu$

So then we conclude that $\theta_1$ is unbiased.

For the second estimator we have this:

$E(\theta_2) = \frac{1}{2} [2E(X_1) -E(X_3) +E(X_5)]=\frac{1}{2} [2\mu -\mu +\mu] = \frac{1}{2} [2\mu]= \mu$

And then we conclude that $\theta_2$ is unbiaed too.

b) For this case first we need to find the variance of each estimator:

$Var(\theta_1) = \frac{1}{49} (Var(X_1) +...+Var(X_7))= \frac{1}{49} (7\sigma^2) = \frac{\sigma^2}{7}$

And for the second estimator we have this:

$Var(\theta_2) = \frac{1}{4} (4\sigma^2 -\sigma^2 +\sigma^2)= \frac{1}{4} (4\sigma^2)= \sigma^2$

And the relative efficiency is given by:

$RE= \frac{Var(\theta_1)}{Var(\theta_2)}=\frac{\frac{\sigma^2}{7}}{\sigma^2}= \frac{1}{7}$

Step-by-step explanation:

For this case we assume that we have a random sample given by: $X_1, X_2,....,X_7$ and each $X_i \sim N (\mu, \sigma)$

Part a

In order to check if an estimator is unbiased we need to check this condition:

$E(\theta) = \mu$

And we can find the expected value of each estimator like this:

$E(\theta_1 ) = \frac{1}{7} E(X_1 +X_2 +... +X_7) = \frac{1}{7} [E(X_1) +E(X_2) +....+E(X_7)]= \frac{1}{7} 7\mu= \mu$

So then we conclude that $\theta_1$ is unbiased.

For the second estimator we have this:

$E(\theta_2) = \frac{1}{2} [2E(X_1) -E(X_3) +E(X_5)]=\frac{1}{2} [2\mu -\mu +\mu] = \frac{1}{2} [2\mu]= \mu$

And then we conclude that $\theta_2$ is unbiaed too.

Part b

For this case first we need to find the variance of each estimator:

$Var(\theta_1) = \frac{1}{49} (Var(X_1) +...+Var(X_7))= \frac{1}{49} (7\sigma^2) = \frac{\sigma^2}{7}$

And for the second estimator we have this:

$Var(\theta_2) = \frac{1}{4} (4\sigma^2 -\sigma^2 +\sigma^2)= \frac{1}{4} (4\sigma^2)= \sigma^2$

And the relative efficiency is given by:

$RE= \frac{Var(\theta_1)}{Var(\theta_2)}=\frac{\frac{\sigma^2}{7}}{\sigma^2}= \frac{1}{7}$

5 0

3 years ago