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3 years ago

Please help me idk this

Mathematics

2 answers:

krek1111 [17]3 years ago

8 0

Answer:

47.1

Step-by-step explanation:

Circumference =2pie radius

radius=1/2 diameter=7.5

2(7.5)3.14=47.1

Rom4ik [11]3 years ago

8 0

Answer:

C =47.1 inches

Step-by-step explanation:

The circumference of a circle is given by

C = pi*d where d is the diameter

C = 3.14 *15

C =47.1 inches

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What is 1812 divided by 4

andrezito [222]

1812/4=
453
The answer is 453

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3 years ago

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\What is the value of x in the equation 2x + 3y = 36, when y = 6?

blsea [12.9K]

Answer:

The value of x in the equation 2x + 3y =36, when y = 6 is 9

Step-by-step explanation:

Solution:

we get 2x + 3(6)= 36

2x + 18 = 36

2x = 36-18

2x = 18

x =9

Hope This Helps You!!!

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2 years ago

A random sample of 16 values is drawn from a mound-shaped and symmetric distribution. The sample mean is 11 and the sample stand

Tpy6a [65]

Answer:

We conclude that the population mean is different from 10.5.

Step-by-step explanation:

We are given that a random sample of 16 values is drawn from a mound-shaped and symmetric distribution. The sample mean is 11 and the sample standard deviation is 2.

We have to test the claim that the population mean is 10.5.

Let, NULL HYPOTHESIS, $H_0$ : $\mu$ = 10.5 {means that the population mean is 10.5}

ALTERNATE HYPOTHESIS, $H_a$ : $\mu \neq$ 10.5 {means that the population mean is different from 10.5}

The test statistics that will be used here is One-sample t-test;

T.S. = $\frac{\bar X - \mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample mean = 11

s = sample standard deviation = 2

$\mu$ = population mean

n = sample of values = 16

So, test statistics = $\frac{11-10.5}{\frac{2}{\sqrt{16} } }$ ~ $t_1_5$

= 1

Now, at 0.05 significance level, t table gives a critical value of 2.131 at 15 degree of freedom. Since our test statistics is way less than the critical value of t so we have insufficient evidence to reject null hypothesis as it will not fall in the rejection region.

Therefore, we conclude that the population mean is different from 10.5.

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4 years ago

If isosceles triangle ABC has a 130° angle at vertex B, which statement must be true?

marshall27 [118]

Answer:

m∠A + m∠B = 155

Step-by-step explanation:

ABC is an isosceles triangle that has a 130° angle at vertex B

then

m∠A = (180 - 130)/2 = 50/2 = 25 = m∠C

then

m∠A = m∠C = 25°

7 0

3 years ago

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The World Health Organization reports that the distribution of ages at time of death in the United States has a mean u of 79.8 y

Alisiya [41]

Answer:

Check explanation

Step-by-step explanation:

Hello!

First, you need to determine your study variable and summarize the information given. This way it'll be easier to answer all questions.

Study variable X: "age of death of an American citizen" (measured in years)
left-skewed distribution
population mean (μ): 79.8 years
population standard derivation (σ): 15.5 years
sample taken (n) 100 death certificates

a. In this question you have to calculate the sample mean (x[bar]) and standard deviation (S), unfortunately, without the sample information, you cannot calculate these two values.

To calculate the sample mean you have to use the formula:

x[bar]: ∑xi/n

And the sample standard deviation

S²: ∑xi² - (∑xi)²/n

S:√S²

b. To answer this item you need to apply the Central Limit Theorem definition to the problem.

This theorem states that given a population with a probability function f (X; μ, σ²) from which a random sample of size n is selected. Then the distribution of the sample mean tends to the normal distribution with mean μ and variance σ²/ n when the sample size tends to infinity (or if the sample size is large enough; n≥30).

With this in mind, you can say that thanks to the Central Limit Theorem, in this example, the sample mean of the age of death of Americans has an approximately Normal distribution X[bar]≈N (79.8; 240.25/100)

c. The probability you need to calculate in this item is P(x(bar)<78)

For this, you need to standardize the variable using the statistical Z=(x[bar]-μ)/(σ²/ n) ≈ N(01;)

P(x[bar]<78) ⇒ P(Z<((78-79.8)/(15.5/√100) ⇒ P(Z<-1.8/1.55) ⇒ P(Z<-1.16) = 0.4364

The probability that the mean age at the time of death in a random sample of 100 American death certificates will be less than 78 years is 0.4364.

I hope you have a SUPER day!

7 0

3 years ago