Answer for brainliest and 10 points

Ayso has 18 8th grade boys teams this year but this is a 28% decrease from the prior year. How many 8th grade teams were there l

NikAS [45]

Answer:

23pupils

Step-by-step explanation:

Given parameters:

Number of 18th grade boys this year = 18

Percentage decrease = 28%

Unknown:

How many 8th grade teams were there last year = ?

Solution:

Since this is a percentage decrease, ;

Number of pupils this year = Number of pupils last year - (28% x 18 )

18 + (28% x 18 ) = Number of pupils last year

Number of pupils last year = 23pupils

4 0

3 years ago

I need helpppp! Please respond, i have to submit this soon.

DedPeter [7]

Answer: y=2x+4

Step-by-step explanation:

the line hits at 4 on the y axis and I did 2 rise, 1 run.

7 0

3 years ago

Read 2 more answers

Frank bought 791 acres of land for a housing development. If 41 acres of his purchase is reserved for a park, how many five-acre

GalinKa [24]

To solve the question, first we will subtract 41 from 791, and we will get 750. Next, we can divide by 5 to figure out how many lots are for purchase, and we get 150! There are 150 five-acre lots available!

6 0

4 years ago

Seventy-two percent of the light aircraft that disappear while in flight in a certain country are subsequently discovered. Of th

Anton [14]

Answer:

a) 0.105 = 10.5% probability that it will not be discovered if it has an emergency locator.

b) 0.522 = 52.2% probability that it will be discovered if it does not have an emergency locator.

c) 0.064 = 6.4% probability that 7 of them are discovered.

Step-by-step explanation:

For itens a and b, we use conditional probability.

For item c, we use the binomial distribution along with the conditional probability.

Conditional Probability

We use the conditional probability formula to solve this question. It is

$P(B|A) = \frac{P(A \cap B)}{P(A)}$

In which

P(B|A) is the probability of event B happening, given that A happened.

$P(A \cap B)$ is the probability of both A and B happening.

P(A) is the probability of A happening.

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.

a) If it has an emergency locator, what is the probability that it will not be discovered?

Event A: Has an emergency locator

Event B: Not located.

Probability of having an emergency locator:

66% of 72%(Are discovered).

20% of 100 - 72 = 28%(not discovered). So

$P(A) = 0.66*0.72 + 0.2*0.28 = 0.5312$

Probability of having an emergency locator and not being discovered:

20% of 28%. So

$P(A cap B) = 0.2*0.28 = 0.056$

Probability:

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.056}{0.5312} = 0.105$

0.105 = 10.5% probability that it will not be discovered if it has an emergency locator.

b) If it does not have an emergency locator, what is the probability that it will be discovered?

Probability of not having an emergency locator:

0.5312 of having. So

$P(A) = 1 - 0.5312 = 0.4688$

Probability of not having an emergency locator and being discovered:

34% of 72%. So

$P(A \cap B) = 0.34*0.72 = 0.2448$

Probability:

$P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.2448}{0.4688} = 0.522$

0.522 = 52.2% probability that it will be discovered if it does not have an emergency locator.

c) If we consider 10 light aircraft that disappeared in flight with an emergency recorder, what is the probability that 7 of them are discovered?

p is the probability of being discovered with the emergency recorder:

0.5312 probability of having the emergency recorder.

Probability of having the emergency recorder and being located:

66% of 72%. So

$P(A \cap B) = 0.66*0.72 = 0.4752$

Probability of being discovered, given that it has the emergency recorder:

$p = P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.4752}{0.5312} = 0.8946$

This question asks for P(X = 7) when $n = 10$ . So

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

$P(X = 7) = C_{10,7}.(0.8946)^{7}.(0.1054)^{3} = 0.064$

0.064 = 6.4% probability that 7 of them are discovered.

8 0

3 years ago

What is the equation of the function represented by this graph?

gayaneshka [121]

Answer:

$\displaystyle g(x) = -(x + 2)(x - 4)$

Step-by-step explanation:

First, look at the graph to determine whether it opens down or up, which in this case is down, so you insert a negative in front of the expression. Next, locate your x-intercepts [zeros (where the graph insects the x-axis)]. You will see that the graph intersects $\displaystyle [-2, 0]$ and $\displaystyle [4, 0],$ so what you do is insert the zeros' OPPOCITES into the equation because according to the vertex equation, $\displaystyle y = A[x - h]^2 + k,$ that negative in front of $\displaystyle h$ gives you the OPPOCITE outcome, so be careful.

I am joyous to assist you at any time.

6 0

3 years ago