What does - |15/-3| equal ?

WILL MARK BRAINLIEST!!! HELP!

deff fn [24]

Answer:

y = 2 sqrt(2) - 2 or y = -2 - 2 sqrt(2) thus B. is the correct answer

Step-by-step explanation:

Solve for y:

-y^2 - 4 y + 4 = 0

Multiply both sides by -1:

y^2 + 4 y - 4 = 0

Add 4 to both sides:

y^2 + 4 y = 4

Add 4 to both sides:

y^2 + 4 y + 4 = 8

Write the left hand side as a square:

(y + 2)^2 = 8

Take the square root of both sides:

y + 2 = 2 sqrt(2) or y + 2 = -2 sqrt(2)

Subtract 2 from both sides:

y = 2 sqrt(2) - 2 or y + 2 = -2 sqrt(2)

Subtract 2 from both sides:

Answer: y = 2 sqrt(2) - 2 or y = -2 - 2 sqrt(2)

4 0

3 years ago

It is estimated that 75% of all young adults between the ages of 18-35 do not have a landline in their homes and only use a cell

Mademuasel [1]

Answer:

a) 75

b) 4.33

c) 0.75

d) $3.2 \times 10^{-13}$ probability that no one in a simple random sample of 100 young adults owns a landline

e) $6.2 \times 10^{-61}$ probability that everyone in a simple random sample of 100 young adults owns a landline.

f) Binomial, with $n = 100, p = 0.75$

g) $4.5 \times 10^{-8}$ probability that exactly half the young adults in a simple random sample of 100 do not own a landline.

Step-by-step explanation:

For each young adult, there are only two possible outcomes. Either they do not own a landline, or they do. The probability of an young adult not having a landline is independent of any other adult, which means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

In which $C_{n,x}$ is the number of different combinations of x objects from a set of n elements, given by the following formula.

$C_{n,x} = \frac{n!}{x!(n-x)!}$

And p is the probability of X happening.

The expected value of the binomial distribution is:

$E(X) = np$

The standard deviation of the binomial distribution is:

$\sqrt{V(X)} = \sqrt{np(1-p)}$

75% of all young adults between the ages of 18-35 do not have a landline in their homes and only use a cell phone at home.

This means that $p = 0.75$

(a) On average, how many young adults do not own a landline in a random sample of 100?

Sample of 100, so $n = 100$

$E(X) = np = 100(0.75) = 75$

(b) What is the standard deviation of probability of young adults who do not own a landline in a simple random sample of 100?

$\sqrt{V(X)} = \sqrt{np(1-p)} = \sqrt{100(0.75)(0.25)} = 4.33$

(c) What is the proportion of young adults who do not own a landline?

The estimation, of 75% = 0.75.

(d) What is the probability that no one in a simple random sample of 100 young adults owns a landline?

This is P(X = 100), that is, all do not own. So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 100) = C_{100,100}.(0.75)^{100}.(0.25)^{0} = 3.2 \times 10^{-13}$

$3.2 \times 10^{-13}$ probability that no one in a simple random sample of 100 young adults owns a landline.

(e) What is the probability that everyone in a simple random sample of 100 young adults owns a landline?

This is P(X = 0), that is, all own. So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 0) = C_{100,0}.(0.75)^{0}.(0.25)^{100} = 6.2 \times 10^{-61}$

$6.2 \times 10^{-61}$ probability that everyone in a simple random sample of 100 young adults owns a landline.

(f) What is the distribution of the number of young adults in a sample of 100 who do not own a landline?

Binomial, with $n = 100, p = 0.75$

(g) What is the probability that exactly half the young adults in a simple random sample of 100 do not own a landline?

This is P(X = 50). So

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 50) = C_{100,50}.(0.75)^{50}.(0.25)^{50} = 4.5 \times 10^{-8}$

$4.5 \times 10^{-8}$ probability that exactly half the young adults in a simple random sample of 100 do not own a landline.

8 0

3 years ago

each sail on the windmill is 5 meters in length How much area do the sails cover as they turn from the force of the wind

melomori [17]

When the windmill turns, its sails will form a circle of 5m radius.

So area = pi*radius^2

= 3.14*5^2

= 3.14*25

= 78.5 sq.m

3 0

3 years ago

The question and answer choices are listed in the picture.

zepelin [54]

Given:
$L=2 \pi r( \frac{x}{360})$

Solution:
If we want to find the solution for r, we need to move the r to the left side first. So I reverse the side
$2 \pi r( \frac{x}{360})=L$

Move 2π to the right side. Because on the left side 2π acts as numerator, after it's moved to the right side, it becomes denominator.
$2 \pi r( \frac{x}{360})=L$
$r( \frac{x}{360})= \frac{L}{2 \pi }$

Move 360 to the right side. Because on the left side 360 acts as denominator, after it's moved to the right side, it becomes numerator.
$r( \frac{x}{360})= \frac{L}{2 \pi }$
$r(x)= \frac{360L}{2 \pi }$

Move x to the right side. Because on the left side x acts as numerator, after it's moved to the right side, it becomes denominator.
$r(x)= \frac{360L}{2 \pi }$
$r= \frac{360L}{2 \pi x}$

Then simplify the fraction
$r= \frac{360L}{2 \pi x}$
$r= \frac{180L}{ \pi x}$

The answer is second option

5 0

3 years ago

What's the formula to find GP?

frosja888 [35]

Answer:

The general form of a GP is a, ar, ar2, ar3 and so on. The nth term of a GP series is Tn = arn-1, where a = first term and r = common ratio = Tn/Tn-1) . The sum of infinite terms of a GP series S∞= a/(1-r) where 0< r<1. If a is the first term, r is the common ratio of a finite G.P.

hope helps

6 0

4 years ago

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