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2 years ago

Can someone help me with this and show the work :) i’ll mark first person brainlyest

Mathematics

1 answer:

weqwewe [10]2 years ago

5 0

Answer:

its probably is B. I am not sure. I wouldnt trust me though but you can if you want. ._.

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(10x+5y)(x-6y) in the simplest form

noname [10]

Answer:

10 $x^{2}$ -55xy-30 $y^{2}$

Step-by-step explanation:

8 0

3 years ago

Read 2 more answers

A professor pays 25 cents for each blackboard error made in lecture to the student who pointsout the error. In a career ofnyears

marta [7]

Answer:

(a) The probability that Y₂₀ exceeds 1000 is 3.91 × 10⁻⁶.

(b) n = 28.09

Step-by-step explanation:

The random variable Yₙ is defined as the total numbers of dollars paid in n years.

It is provided that Yₙ can be approximated by a Gaussian distribution, also known as Normal distribution.

The mean and standard deviation of Yₙ are:

$\mu_{Y_{n}}=40n\\\sigma_{Y_{n}}=\sqrt{100n}$

(a)

For n = 20 the mean and standard deviation of Y₂₀ are:

$\mu_{Y_{n}}=40n=40\times20=800\\\sigma_{Y_{n}}=\sqrt{100n}=\sqrt{100\times20}=44.72\\$

Compute the probability that Y₂₀ exceeds 1000 as follows:

$P(Y_{n}>1000)=P(\frac{Y_{n}-\mu_{Y_{n}}}{\sigma_{Y_{n}}}>\frac{1000-800}{44.72})\\=P(Z> 4.47)\\=1-P(Z$

**Use a z table for probability.

Thus, the probability that Y₂₀ exceeds 1000 is 3.91 × 10⁻⁶.

(b)

It is provided that P (Yₙ > 1000) > 0.99.

$P(Y_{n}>1000)=0.99\\1-P(Y_{n}$

The value of z for which P (Z < z) = 0.01 is 2.33.

Compute the value of n as follows:

$z=\frac{Y_{n}-\mu_{Y_{n}}}{\sigma_{Y_{n}}}\\2.33=\frac{1000-40n}{\sqrt{100n}}\\2.33=\frac{100}{\sqrt{n}}-4\sqrt{n} \\2.33=\frac{100-4n}{\sqrt{n}} \\5.4289=\frac{(100-4n)^{2}}{n}\\5.4289=\frac{10000+16n^{2}-800n}{n}\\5.4289n=10000+16n^{2}-800n\\16n^{2}-805.4289n+10000=0$

The last equation is a quadratic equation.

The roots of a quadratic equation are:

$n=\frac{-b\pm\sqrt{b^{2}-4ac}}{2a}$

a = 16

b = -805.4289

c = 10000

On solving the last equation the value of n = 28.09.

8 0

3 years ago

7.) If a circle has a diameter of 40 inches, what is the same circles radius?

My name is Ann [436]

The radius is always half of the diameter so it would be 20 inches

5 0

2 years ago

The weights of the fish in a certain lake are normally distributed with a mean of 11 lb and a standard deviation of 6. if 4 fish

Alexus [3.1K]

Since the sample standard deviation is now known, we use the z-score test. The formula is given as:

z= (X – μ) / (s / sqrt(n))

Where,

X = sample mean = 8.6 lb to 14.6 lb

μ = population mean = 11 lb

s = population standard deviation = 6

n = sample size = 4

1st: Calculating for z when x = 8.6 lb

z = (8.6 – 11) / (6 / sqrt4)

z = - 0.8

Using the standard distribution table for z:

Probability (x = 8.6 lb) = 0.2119

2nd: Calculating for z when x = 14.6 lb

z = (14.6 – 11) / (6 / sqrt4)

z = 1.2

Using the standard distribution table for z:

Probability (x = 14.6 lb) = 0.8849

Therefore the probability that the mean weight will be between 8.6 and 14.6 lb:

Probability (8.6 ≤ x ≤ 14.6 ) = 0.8849 - 0.2119

Probability (8.6 ≤ x ≤ 14.6 ) = 0.673 (ANSWER)

8 0

2 years ago

What is DA equal to? Brainiest if correct and please show your answer.

Naddik [55]

Answer:

<h2>DA is equal to 25 or BA</h2>

Step-by-step explanation:

ABC

ADC

Since we know that line CA is equal to line CA because of reflexive property
Angle BAC and DAC are equal because of definition of an angle bisector
Angle ABC and ADC are equal because of definition of an angle bisector
This will give us ASA, proving to us that all sides and angles are congruent (this was already given to us)
So, if BA is 25, and we know that BA is congruent to DA, this tells us that DA is 25

5 0

1 year ago