All categories

3 years ago

PLZ HELP

Mathematics

1 answer:

SVEN [57.7K]3 years ago

3 0

Answer:

This is the answer, dont forget to change the wording or you'll get a plagiarism strike.

Step-by-step explanation:

You might be interested in

Kim places £500 in a bank account the pays 3% simple interest each year

IgorLugansk [536]

She will gain 3% each year and after one year she will gain £15 leaving her total at £515

8 0

4 years ago

Jane must get at least three of the four problems on the exam correct to get an A. She has been able to do 80% of the problems o

NISA [10]

Answer:

a) There is n 81.92% probability that she gets an A.

b) If she gets the first problem correct, there is an 89.6% probability that she gets an A.

Step-by-step explanation:

For each question, there are only two possible outcomes. Either the answer is correct, or it is not. This means that we can solve this problem using binomial distribution probability concepts.

Binomial probability distribution

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

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

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

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

And $\pi$ is the probability of X happening.

For this problem, we have that:

The probability she gets any problem correct is 0.8, so $\pi = 0.8$ .

(a) What is the probability she gets an A?

There are four problems, so $n = 4$

Jane must get at least three of the four problems on the exam correct to get an A.

So, we need to find $P(X \geq 3)$

$P(X \geq 3) = P(X = 3) + P(X = 4)$

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

$P(X = 3) = C_{4,3}.(0.80)^{3}.(0.2)^{1} = 0.4096$

$P(X = 4) = C_{4,4}.(0.80)^{4}.(0.2)^{0} = 0.4096$

$P(X \geq 3) = P(X = 3) + P(X = 4) = 2*0.4096 = 0.8192$

There is n 81.92% probability that she gets an A.

(b) If she gets the first problem correct, what is the probability she gets an A?

Now, there are only 3 problems left, so $n = 3$

To get an A, she must get at least 2 of them right, since one(the first one) she has already got it correct.

So, we need to find $P(X \geq 2)$

$P(X \geq 3) = P(X = 2) + P(X = 3)$

$P(X = 2) = C_{3,2}.(0.80)^{2}.(0.2)^{1} = 0.384$

$P(X = 4) = C_{3,3}.(0.80)^{3}.(0.2)^{0} = 0.512$

$P(X \geq 3) = P(X = 2) + P(X = 3) = 0.384 + 0.512 = 0.896$

If she gets the first problem correct, there is an 89.6% probability that she gets an A.

3 0

4 years ago

A 445-foot fence encloses a pasture. What is the length of each side of the pasture?

fredd [130]

Answer:

89*5

Step-by-step explanation:

3 0

3 years ago

On a hot day, a football team drank an entire 50-gallon cooler of water and half as much again. How much water did they drink?

NemiM [27]

Answer:

The football team drank a total of 75 gallons of water.

Step-by-step explanation:

Half of 50 gallons is 25 gallons. 25 gallons + 50 gallons = 75 gallons.

7 0

3 years ago

Read 2 more answers

What is the difference of the polynomials? (–2x3y2 + 4x2y3 – 3xy4) – (6x4y – 5x2y3 – y5)

ANEK [815]

For the answer to the question above, I'll provide my solutions to my answers for the problem below.

(–2x3y2 + 4x2y3 – 3xy4) – (6x4y – 5x2y3 – y5)

(−2x3)(y2)+4x2y3+−3xy4+−1(6x4y)+−1(−5x2y3)+−1(−y5)

(−2x3)(y2)+4x2y3+−3xy4+−6x4y+5x2y3+y5

−2x3y2+4x2y3+−3xy4+−6x4y+5x2y3+y5

−2x3y2+4x2y3+−3xy4+−6x4y+5x2y3+y5

(−6x4y)+(−2x3y2)+(4x2y3+5x2y3)+(−3xy4)+(y5)

−6x4y+−2x3y2+9x2y3+−3xy4+y5
So the answer is,
= −6x4y−2x3y2+9x2y3−3xy4+y5

I hope this helps

4 0

4 years ago

Read 2 more answers