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
garri49 [273]
3 years ago
7

Three- eighths of the seventh grade students were taking advanced math at the beginning of the year,but seven dropped out by the

end of the year. If there were 140 students taking advanced math at the end of the year,how many total 7th grade students are there ?
Mathematics
1 answer:
vekshin13 years ago
7 0

392 because if there are 147 taking advanced math at the end of the year then 147 x 3/8 = 392

You might be interested in
The quadrilateral has vertices A(3,5), B(2,0), C(7,0) and D(8,5). Which statement about the quadrilateral is true
viktelen [127]

It is a parallelogram!

Also you haven't really put any other info...

7 0
3 years ago
4. A random variable X has a mean of 10 and a standard deviation of 3. If 2 is added to each value of X, what will the new mean
Ede4ka [16]

Adding 2 to each value of the random variable X makes a new random variable X+2. Its mean would be

E[X+2]=E[X]+E[2]=E[X]+2

since expectation is linear, and the expected value of a constant is that constant. E[X] is the mean of X, so the new mean would be

E[X+2]=10+2=12

The variance of a random variable X is

V[X]=E[X^2]-E[X]^2

so the variance of X+2 would be

V[X+2]=E[(X+2)^2]-E[X+2]^2

We already know E[X+2]=12, so simplifying above, we get

V[X+2]=E[X^2+4X+4]-12^2

V[X+2]=E[X^2]+4E[X]+4-12^2

V[X+2]=(V[X]+E[X]^2)+4E[X]-140

Standard deviation is the square root of variance, so V[X]=3^2=9.

\implies V[X+2]=(9+10^2)+4(10)-140=9

so the standard deviation remains unchanged at 3.

NB: More generally, the variance of aX+b for a,b\in\mathbb R is

V[aX+b]=a^2V[X]+b^2V[1]

but the variance of a constant is 0. In this case, a=1, so we're left with V[X+2]=V[X], as expected.

5 0
3 years ago
A piece of wire is 72cm long. Is used to form 2 identical squares. What is the length of each each side of squares?
Sedbober [7]

Answer:

the length of each side of the square are 6 cm

4 0
3 years ago
Read 2 more answers
Solve for the variable. find all solutions if any exist. (please show work)
Gwar [14]
16. q-8=14
add 8 on both sides
q=22
8 0
3 years ago
Gavin drank 3/4 of a liter of orange juice from a container, which was 3/8 of the orange juice that was originally in the contai
Sliva [168]
X= amount of orange juice in the beginning
3/4=(3/8)X
.75=.375X
.75/.375=X
X=2
there were 2 liters in the beginning 
7 0
3 years ago
Other questions:
  • The volume of a tissue box is 288in3. If the box has a width of 6 inches and it is 4 inches high, how long is the box?
    13·1 answer
  • A town’s population went from 35,000 to 42,000 in 3 years. What was the percent of change?
    7·1 answer
  • If I said 15402,How It could be in 2 significant?
    10·2 answers
  • You will be brainliest please list correct answer and the mistake he made
    14·1 answer
  • Someone pls help me :((((
    15·1 answer
  • Need help on this please and thank you
    8·2 answers
  • The student council is making corsages to sell at prom. They spent $350 on materials such as
    9·1 answer
  • Which statement correctly compares the two functions shown?
    13·1 answer
  • Evaluate the function.<br> f(x) = -x² +6<br> Find f(-1)
    5·2 answers
  • F(x) = -2 and g(x) = 2x² + x-3, find (f +g)(x) .
    12·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!