1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Fudgin [204]
3 years ago
15

78 % of the class scored a C or above on their test. If there are 35 students in the class, how many scored a C or higher? Write

and solve a proportion for this situation.
Mathematics
2 answers:
konstantin123 [22]3 years ago
5 0

Answer:

27 students

Step-by-step explanation:

\frac{78}{100} =\frac{x}{35} \\

cross multiply and you get 27

ratelena [41]3 years ago
3 0

All this question is trying to ask is to find 78% percent of the total number of student in the class.

So first convert 78 to decimal by dividing it by 100: \frac{78}{100} = 0.78

Next multiply that with the total number of students which is 35.

So, 0.78 * 35 = 27.3

Now I don't think there can be a decimal here. The question must be wrong or the percentage might be incorrect. But, just for sake, we'll round it up so the final answer would be: 27

The proportion would be: 273:10

You might be interested in
What is the area, in square inches, of the rectangle below?
chubhunter [2.5K]
The answer would be D i believe
6 0
2 years ago
What fractions are equivalent to 28/32
marin [14]
The answer is 7/8. 28/4 = 7, 32/4=8.
7 0
2 years ago
Read 2 more answers
Rachel earned \$34$34 in 44 hours at her job today. She wants to know how much she could earn (e)(e) tomorrow if she works 1010
kari74 [83]

Answer:

<em>Rachel will earn $85 in 10 hours.</em>

Step-by-step explanation:

Rachel earned $34 in 4 hours at her job today.

Suppose, she will earn x dollar in 10 hours tomorrow.

So, <u>according to ratio of 'dollar' and 'hours'</u>, the equation will be.....

\frac{34}{4}=\frac{x}{10}

After cross multiplying, we will get.....

4x= 34*10\\ \\ 4x= 340\\ \\ x=\frac{340}{4}=85

Thus, Rachel will earn $85 in 10 hours.

6 0
2 years ago
Read 2 more answers
Is the sequence geometric? If so, identify the common ratio. 6, 12, 24, 48, ...
Artist 52 [7]
Yes. It is a Geometric sequence!
Common ratio = a2/a1 = 12/6 = 2

In short, Your Answer would be Option A

Hope this helps!
5 0
3 years ago
Solve the following differential equation using using characteristic equation using Laplace Transform i. ii y" +y sin 2t, y(0) 2
kifflom [539]

Answer:

The solution of the differential equation is y(t)= - \frac{1}{3} Sin(2t)+2 Cos(t)+\frac{5}{3} Sin(t)

Step-by-step explanation:

The differential equation is given by: y" + y = Sin(2t)

<u>i) Using characteristic equation:</u>

The characteristic equation method assumes that y(t)=e^{rt}, where "r" is a constant.

We find the solution of the homogeneus differential equation:

y" + y = 0

y'=re^{rt}

y"=r^{2}e^{rt}

r^{2}e^{rt}+e^{rt}=0

(r^{2}+1)e^{rt}=0

As e^{rt} could never be zero, the term (r²+1) must be zero:

(r²+1)=0

r=±i

The solution of the homogeneus differential equation is:

y(t)_{h}=c_{1}e^{it}+c_{2}e^{-it}

Using Euler's formula:

y(t)_{h}=c_{1}[Sin(t)+iCos(t)]+c_{2}[Sin(t)-iCos(t)]

y(t)_{h}=(c_{1}+c_{2})Sin(t)+(c_{1}-c_{2})iCos(t)

y(t)_{h}=C_{1}Sin(t)+C_{2}Cos(t)

The particular solution of the differential equation is given by:

y(t)_{p}=ASin(2t)+BCos(2t)

y'(t)_{p}=2ACos(2t)-2BSin(2t)

y''(t)_{p}=-4ASin(2t)-4BCos(2t)

So we use these derivatives in the differential equation:

-4ASin(2t)-4BCos(2t)+ASin(2t)+BCos(2t)=Sin(2t)

-3ASin(2t)-3BCos(2t)=Sin(2t)

As there is not a term for Cos(2t), B is equal to 0.

So the value A=-1/3

The solution is the sum of the particular function and the homogeneous function:

y(t)= - \frac{1}{3} Sin(2t) + C_{1} Sin(t) + C_{2} Cos(t)

Using the initial conditions we can check that C1=5/3 and C2=2

<u>ii) Using Laplace Transform:</u>

To solve the differential equation we use the Laplace transformation in both members:

ℒ[y" + y]=ℒ[Sin(2t)]

ℒ[y"]+ℒ[y]=ℒ[Sin(2t)]  

By using the Table of Laplace Transform we get:

ℒ[y"]=s²·ℒ[y]-s·y(0)-y'(0)=s²·Y(s) -2s-1

ℒ[y]=Y(s)

ℒ[Sin(2t)]=\frac{2}{(s^{2}+4)}

We replace the previous data in the equation:

s²·Y(s) -2s-1+Y(s) =\frac{2}{(s^{2}+4)}

(s²+1)·Y(s)-2s-1=\frac{2}{(s^{2}+4)}

(s²+1)·Y(s)=\frac{2}{(s^{2}+4)}+2s+1=\frac{2+2s(s^{2}+4)+s^{2}+4}{(s^{2}+4)}

Y(s)=\frac{2+2s(s^{2}+4)+s^{2}+4}{(s^{2}+4)(s^{2}+1)}

Y(s)=\frac{2s^{3}+s^{2}+8s+6}{(s^{2}+4)(s^{2}+1)}

Using partial franction method:

\frac{2s^{3}+s^{2}+8s+6}{(s^{2}+4)(s^{2}+1)}=\frac{As+B}{s^{2}+4} +\frac{Cs+D}{s^{2}+1}

2s^{3}+s^{2}+8s+6=(As+B)(s²+1)+(Cs+D)(s²+4)

2s^{3}+s^{2}+8s+6=s³(A+C)+s²(B+D)+s(A+4C)+(B+4D)

We solve the equation system:

A+C=2

B+D=1

A+4C=8

B+4D=6

The solutions are:

A=0 ; B= -2/3 ; C=2 ; D=5/3

So,

Y(s)=\frac{-\frac{2}{3} }{s^{2}+4} +\frac{2s+\frac{5}{3} }{s^{2}+1}

Y(s)=-\frac{1}{3} \frac{2}{s^{2}+4} +2\frac{s }{s^{2}+1}+\frac{5}{3}\frac{1}{s^{2}+1}

By using the inverse of the Laplace transform:

ℒ⁻¹[Y(s)]=ℒ⁻¹[-\frac{1}{3} \frac{2}{s^{2}+4}]-ℒ⁻¹[2\frac{s }{s^{2}+1}]+ℒ⁻¹[\frac{5}{3}\frac{1}{s^{2}+1}]

y(t)= - \frac{1}{3} Sin(2t)+2 Cos(t)+\frac{5}{3} Sin(t)

3 0
3 years ago
Other questions:
  • A part of a line with endpoints on both ends is a(n):
    9·1 answer
  • Inter quartile range is
    7·1 answer
  • A circular lawn has a row of bricks aroumd the edge. The diameter ofnthe lawnis Bout 40 feet. Which is best estimate for the amo
    8·1 answer
  • PIck from smallest to largest Smallest 8.008 8.018 8.088 8.88 8.808 Largest
    13·1 answer
  • 35. A pilot can travel 400 miles with the win
    14·1 answer
  • ILL GIVE BRAINLIEST TO THE FIRST PERSON TO ANSWER THIS
    5·1 answer
  • Am I right vote you brainiest
    5·1 answer
  • PLEASEEEEE HELPPPPP ASAPPPPP
    6·1 answer
  • Candy and Hershel folded the same-size square papers.
    14·1 answer
  • A cylinder. A is the height, B is the base, C is the diameter, D is the radius.
    13·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!