All categories

3 years ago

Max earned a 85% on his test. if there were 40 questions on the test how many did he get correct?

1 answer:

wel3 years ago

3 0

Max would have had to have gotten 34 out of 40 questions correct. Here's why:

$\frac{x}{40} = \frac{85}{100} 

(40)(85) = (x)(100)



3400 = 100x

 \frac{3400}{100} = x


34 =x
$

You might be interested in

The difference of c and 2 is greater than or equal to -22

Charra [1.4K]

You can write the question as a inequality.

c - 2 ≥ -22
add 2 on both sides...

c ≥ -20

Your answer is c ≥ -20.

7 0

3 years ago

Trevon is helping his sister study for her geometry test while staying at a hotel.

Serhud [2]

Option (C) -: The hotel floors are parallel to each other, and the elevator moves in a path that is perpendicular to them both.

<h3>What is parallel and perpendicular ?</h3>

In geometry two lines are parallel to each other when they have no intersecting point and the distance between them is constant.

Two lines are perpendicular if they have an intersecting point and they intersect each other at at 90°.

From the given figure we can observe the distance between the floor ceiling of 3rd and 6th floor is constant therefore they are parallel to each other.Now if we imagine the elevator going up and down an imaginary line (meeting line of two elevator doors) would intersect them at an angle of 90°.

∴The hotel floors are parallel to each other, and the elevator moves in a path that is perpendicular to them both.

Learn more about parallel and perpendicular here :

brainly.com/question/16853486

#SPJ1

5 0

2 years ago

A rectangular pyramid has a volume of 160 cubic feet. Find two possible sets of measurements for the base area and height of the

muminat

$\bf \textit{volume of a pyramid}\\\\ V=\cfrac{1}{3}Bh~~ \begin{cases} B=area~of\\ \qquad its~base\\ h=height\\ \cline{1-1} V=160 \end{cases}\implies 160=\cfrac{Bh}{3}\implies 480=Bh \\\\[-0.35em] ~\dotfill\\\\ \begin{cases} 480=&2\cdot 2\cdot 2\cdot 2\cdot 2\cdot 3\cdot 5\\ &8\cdot 60\\ &32\cdot 15 \end{cases}~\hspace{5em}\stackrel{B}{8}\times\stackrel{h}{60}\qquad \qquad \stackrel{B}{32}\times\stackrel{h}{15}$

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

the length of this prism is multiplied by a scale factor of 1/2 to create rectangular prism B the volume of rectangular prism B

anastassius [24]

We know that

[volume of rectangular prism]=L*W*h
L= 6 in prism A
volume of rectangular prism A=6*w*h

L=6*(1/2)------> L=3 in prism B

volume of rectangular prism B=3*w*h
so
volume of rectangular prism B=[volume of rectangular prism A]/2

the answer is
Volume of B is 1/2 volume of A

8 0

3 years ago