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2 years ago

What is the area of a circle with diameter 15 cm? Round your answer to the nearest tenth.

Mathematics

1 answer:

Len [333]2 years ago

6 0

Answer:

176.8

Step-by-step explanation: first you have to find the radius by finding the half of 15 which is calculated to be 7.5

and the formula to find the area is A= $\pi 7.5^{2} \\$

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Which value is equivalent to Check the picture

myrzilka [38]

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2 years ago

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How many times does 4 go into 78

Bess [88]

You would do 78/4 which equals 19.5. Hope this helps!

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3 years ago

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Consider H0: μ = 45 versus H1: μ < 45. A random sample of 25 observations produced a sample mean of 41.8. Using α = .025 and

a_sh-v [17]

Given
$H0: \ \mu=45 \\ \\ H1: \ \mu\ \textless \ 45$
This is a one-tailed test.

$z= \frac{41.8-45}{6/ \sqrt{25} } = \frac{-3.2}{6/5} = \frac{-3.2}{1.2} =-2.6667$

$P(z\ \textless \ -2.6667)=0.00383$

Since the p-value of the sample statistic (0.00383) is less that the significant level (0.025), we reject the null hypothesis.

5 0

3 years ago

Solve the Anti derivative.

Alex Ar [27]

Answer:

$\displaystyle \int {\frac{1}{9x^2+4}} \, dx = \frac{1}{6}arctan(\frac{3x}{2}) + C$

General Formulas and Concepts:

Algebra I

Factoring

Calculus

Antiderivatives - integrals/Integration

Integration Constant C

U-Substitution

Integration Property [Multiplied Constant]: $\displaystyle \int {cf(x)} \, dx = c \int {f(x)} \, dx$

Trig Integration: $\displaystyle \int {\frac{du}{a^2 + u^2}} = \frac{1}{a}arctan(\frac{u}{a}) + C$

Step-by-step explanation:

Step 1: Define

$\displaystyle \int {\frac{1}{9x^2 + 4}} \, dx$

Step 2: Integrate Pt. 1

[Integral] Factor fraction denominator: $\displaystyle \int {\frac{1}{9(x^2 + \frac{4}{9})}} \, dx$
[Integral] Integration Property - Multiplied Constant: $\displaystyle \frac{1}{9} \int {\frac{1}{x^2 + \frac{4}{9}}} \, dx$

Step 3: Identify Variables

Set up u-substitution for the arctan trig integration.

$\displaystyle u = x \\ a = \frac{2}{3} \\ du = dx$

Step 4: Integrate Pt. 2

[Integral] Substitute u-du: $\displaystyle \frac{1}{9} \int {\frac{1}{u^2 + (\frac{2}{3})^2} \, du$
[Integral] Trig Integration: $\displaystyle \frac{1}{9}[\frac{1}{\frac{2}{3}}arctan(\frac{u}{\frac{2}{3}})] + C$
[Integral] Simplify: $\displaystyle \frac{1}{9}[\frac{3}{2}arctan(\frac{3u}{2})] + C$
[integral] Multiply: $\displaystyle \frac{1}{6}arctan(\frac{3u}{2}) + C$
[Integral] Back-Substitute: $\displaystyle \frac{1}{6}arctan(\frac{3x}{2}) + C$