Isabella flew 600 miles in 120 minutes. How many miles per minuite did she fly

The volume of a right cylinder is 2,000π cubic feet, and the height is 20 feet. What is the length of the radius in feet?

laila [671]

Answer:

r = 10 ft

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Multiplication Property of Equality
Division Property of Equality
Addition Property of Equality
Subtraction Property of Equality

Geometry

Volume of a Cylinder Formula: V = πr²h

r is radius
h is height

Step-by-step explanation:

Step 1: Define

Identify variables

Volume V = 2000π ft³

Height h = 20 ft

Radius r = unknown

Step 2: Solve for r

Substitute in variables [Volume of a Right Cylinder Formula]: 2000π ft³ = πr²(20 ft)
[Division Property of Equality] Isolate r term: 100 ft² = r²
Rewrite: r² = 100 ft²
[Equality Property] Square root both sides: r = 10 ft

8 0

3 years ago

Which is the best estimate for the product of 104.143 * 10,021.4

Lilit [14]

1,000,000

Explain: 100 x 10,000 = 1,000,000 just round then multiply

4 0

4 years ago

on my old account i had over 2000 points but then i lost all of it and now i have -600 points so i made this account dabdab

Naddik [55]

Answer:

so lost is 1400

Step-by-step explanation:

You lost 2000 points but now you have 600 so you have 1400 points to bring back

7 0

3 years ago

Read 2 more answers

The TreeDropp’d Fruit Company wants to sell its apples overseas in attractive pink and yellow gift boxes. To design the boxes, t

SashulF [63]

Answer:

a)For this case the best estimator for the true mean is the sample mean $\hat \mu =\bar X$ because:

$E(\bar X)= \frac{\sum_{i=1}^n E(X_i)}{n}$

And if we assume that each observation $X_1 , X_2,...,X_n$ follows a normal distribution $X_i \sim N(\mu,\sigma)$ then we have:

$E(\bar X)=\frac{1}{n} n\mu =\mu$

So then yes the $\bar X[/tex[ is a unbiased estimator for the true mean. b) [tex]z_{\alpha/2}=1.96$

c) $ME= 1.96 \frac{0.4}{\sqrt{50}}=0.1109$

Step-by-step explanation:

Previous concepts

The margin of error is the range of values below and above the sample statistic in a confidence interval.

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

$\bar X=4.1$ represent the sample mean

$\mu$ population mean (variable of interest)

$\sigma=0.4$ represent the population standard deviation

n=50 represent the sample size

Assuming the X follows a normal distribution

$X \sim N(\mu, \sigma=0.4$

The sample mean $\bar X$ is distributed on this way:

$\bar X \sim N(\mu, \frac{\sigma}{\sqrt{n}})$

A. What is the point estimate in this scenario? Is it an unbiased estimator?

For this case the best estimator for the true mean is the sample mean $\hat \mu =\bar X$ because:

$E(\bar X)= \frac{\sum_{i=1}^n E(X_i)}{n}$

And if we assume that each observation $X_1 , X_2,...,X_n$ follows a normal distribution $X_i \sim N(\mu,\sigma)$ then we have:

$E(\bar X)=\frac{1}{n} n\mu =\mu$

So then yes the $\bar X[/tex[ is a unbiased estimator for the true mean. B. What is the critical z-value for a 95% interval?
The next step would be find the value of [tex]\z_{\alpha/2}$ , $\alpha=1-0.95=0.05$ and $\alpha/2=0.025$

Using the normal standard table, excel or a calculator we see that:

$z_{\alpha/2}=1.96$

C. What is the margin of error for a 95% interval in this scenario? Show your work.

The margin of error is given by:

$ME= z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$

If we replace the values that we have we got:

$ME= 1.96 \frac{0.4}{\sqrt{50}}=0.1109$

The confidence interval on this case is given by:

$\bar X \pm z_{\alpha/2}\frac{\sigma}{\sqrt{n}}$ (1)

Since we have all the values we can replace:

$4.1 - 1.96\frac{0.4}{\sqrt{50}}=3.989$

$4.1 + 1.96\frac{0.4}{\sqrt{50}}=4.211$

So on this case the 95% confidence interval would be given by (3.989;4.211)

4 0

3 years ago

Which is the best estimate for StartFraction (8.9 times 10 Superscript 8 Baseline) Over (3.3 times 10 Superscript 4 Baseline) En

ratelena [41]

Answer:

$2.7 * 10^{4}$

Step-by-step explanation:

Given the expression $\frac{8.9*10^{8} }{3.3*10^{4} }$ , to express the the fraction in scientific notation, we will apply the law of indices below;

According to one of the laws of indices, $\frac{a^{m} }{a^{n} } = a^{m-n}$

Applying this to the fraction;

$= \frac{8.9*10^{8} }{3.3*10^{4} }\\\\= \frac{8.9}{3.3} * \frac{10^{8} }{10^{4} }\\\\ = \frac{8.9}{3.3} * 10^{8-4}\\\\ = \frac{8.9}{3.3} *10^{4}\\\\ = 2.697 * 10^{4}$

The best estimate for the fraction in scientific notation will be $2.7 * 10^{4}$

8 0

4 years ago

Read 2 more answers