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3 years ago

11

What is the answer to -2•4.1/1

1 answer:

gladu [14]3 years ago

4 0

Just put into a calculator.
2*4.1/1
= -2*4.1 = -8.2

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To find the inverse of the function, change f(x)=x+3

Neko [114]

Answer:

Step-by-step explanation:

X×X/2+3X+C

4 0

3 years ago

According to the Knot, 22% of couples meet online. Assume the sampling distribution of p follows a normal distribution and answe

Ann [662]

Using the <em>normal distribution and the central limit theorem</em>, we have that:

a) The sampling distribution is approximately normal, with mean 0.22 and standard error 0.0338.

b) There is a 0.1867 = 18.67% probability that in a random sample of 150 couples more than 25% met online.

c) There is a 0.2584 = 25.84% probability that in a random sample of 150 couples between 15% and 20% met online.

<h3>Normal Probability Distribution</h3>

In a normal distribution with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

It measures how many standard deviations the measure is from the mean.

After finding the z-score, we look at the z-score table and find the p-value associated with this z-score, which is the percentile of X.

By the Central Limit Theorem, for a proportion p in a sample of size n, the sampling distribution of sample proportion is approximately normal with mean $\mu = p$ and standard deviation $s = \sqrt{\frac{p(1 - p)}{n}}$ , as long as $np \geq 10$ and $n(1 - p) \geq 10$ .

In this problem:

22% of couples meet online, hence p = 0.22.

A sample of 150 couples is taken, hence n = 150.

Item a:

The mean and the standard error are given by:

$\mu = p = 0.22$

$s = \sqrt{\frac{p(1 - p)}{n}} = \sqrt{\frac{0.22(0.78)}{150}} = 0.0338$

The sampling distribution is approximately normal, with mean 0.22 and standard error 0.0338.

Item b:

The probability is <u>one subtracted by the p-value of Z when X = 0.25</u>, hence:

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem:

$Z = \frac{X - \mu}{s}$

$Z = \frac{0.25 - 0.22}{0.0338}$

Z = 0.89

Z = 0.89 has a p-value of 0.8133.

1 - 0.8133 = 0.1867.

There is a 0.1867 = 18.67% probability that in a random sample of 150 couples more than 25% met online.

Item c:

The probability is the <u>p-value of Z when X = 0.2 subtracted by the p-value of Z when X = 0.15</u>, hence:

X = 0.2:

$Z = \frac{X - \mu}{s}$

$Z = \frac{0.2 - 0.22}{0.0338}$

Z = -0.59

Z = -0.59 has a p-value of 0.2776.

X = 0.15:

$Z = \frac{X - \mu}{s}$

$Z = \frac{0.15 - 0.22}{0.0338}$

Z = -2.07

Z = -2.07 has a p-value of 0.0192.

0.2776 - 0.0192 = 0.2584.

There is a 0.2584 = 25.84% probability that in a random sample of 150 couples between 15% and 20% met online.

To learn more about the <em>normal distribution and the central limit theorem</em>, you can check brainly.com/question/24663213

4 0

3 years ago

Original price of a sofa: $620.00<br> Discount: 25%, Selling Price?

Aleks [24]

Answer:

x=155

Step-by-step explanation:

I hope the pictures are clear and you get the concept!

3 0

3 years ago

CAN SOMEONE HELP PLEASE <br> m4A=42°, b=10, c= 12. What is the length of a to the nearest tenth?

kipiarov [429]

<u>Answer:</u>

a = 8.1

<u>Step-by-step explanation:</u>

Use the cosine rule:

$a = \sqrt{b^2 + c^2 -2 bc \space\ cosA }$

Substituting the values:

$a = \sqrt{10^2 + 12^2 -2(10)(12) \space\ cos 42 \textdegree\ }$

⇒ $a = \sqrt{4 \space\ cos 42\textdegree\ }$

⇒ $a = 8.1$

4 0

2 years ago

I need the answers to #1,#2 and #3

Ede4ka [16]

The answers are #1 45 #2 24 #3 10

6 0

3 years ago