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
olganol [36]
3 years ago
12

The students at a school are voting on their favorite type of music. Charles surveys a representative sample of students to dete

rmine for which type of music each student will vote. The results are in the table below.
STUDENT VOTES
Type of Music Number of Votes
Hip Hop 21
Jazz 15
Classic Rock 9
Punk 6
Charles thinks that if all 850 students vote, 355 students will vote for jazz.

By how many students is his prediction off?

Enter your answer in the box.
Mathematics
1 answer:
Tpy6a [65]3 years ago
5 0
Wait wouldn’t it just be subtracting 355 from 15 cause if so your answer is 340 but I’m not to sure
You might be interested in
Assume that T is a linear transformation. Find the standard matrix of T. T: R^3 right arrow R^2 , T(e 1) =(1,2), and T(e2 ) =( -
irina [24]

Answer:

A = \left[\begin{array}{ccc}1&-4&2\\2&6&-6\end{array}\right]

Step-by-step explanation:

Given

T:R^3->R^2

T(e_1) = (1,2)

T(e_2) = (-4,6)

T(e_3) = (2,-6)

Required

Find the standard matrix

The standard matrix (A) is given by

Ax = T(x)

Where

T(x) = [T(e_1)\ T(e_2)\ T(e_3)]\left[\begin{array}{c}x_1&x_2&x_3\\-&&x_n\end{array}\right]

Ax = T(x) becomes

Ax = [T(e_1)\ T(e_2)\ T(e_3)]\left[\begin{array}{c}x_1&x_2&x_3\\-&&x_n\end{array}\right]

The x on both sides cancel out; and, we're left with:

A = [T(e_1)\ T(e_2)\ T(e_3)]

Recall that:

T(e_1) = (1,2)

T(e_2) = (-4,6)

T(e_3) = (2,-6)

In matrix:

(a,b) is represented as: \left[\begin{array}{c}a\\b\end{array}\right]

So:

T(e_1) = (1,2) = \left[\begin{array}{c}1\\2\end{array}\right]

T(e_2) = (-4,6)=\left[\begin{array}{c}-4\\6\end{array}\right]

T(e_3) = (2,-6)=\left[\begin{array}{c}2\\-6\end{array}\right]

Substitute the above expressions in A = [T(e_1)\ T(e_2)\ T(e_3)]

A = \left[\begin{array}{ccc}1&-4&2\\2&6&-6\end{array}\right]

Hence, the standard of the matrix A is:

A = \left[\begin{array}{ccc}1&-4&2\\2&6&-6\end{array}\right]

6 0
3 years ago
How do you find the vertex of this parabola? I just plotted the points down on a graphing calculator, but I figure there's a bet
Sergio039 [100]
When you look at the table, find the y value that has equivalent values on both sides. For example, the y value for the vertex here is 10. After it, the values are 7,-2, and 17, and above it, the values are 7 and -2. This value should also be either the largest y value or smallest y value (depending on whether the parabola opens up or down).
3 0
3 years ago
It took you 120 minutes to work 15 math problems. How long did you spend on<br> each problem
Karolina [17]

Answer:

8 minutes

Step-by-step explanation:

120÷ 15= 8

yup thats pretty much it

5 0
2 years ago
Read 2 more answers
The number of problems that the math team successfully solved at this year's competition increased from last year by a factor of
Maksim231197 [3]
Earlier today I set you ten questions from this year’s International Singapore Maths Competition. Here are the questions and the answers. On the whole you did very well - smarter than a 10-year-old Singaporean! (With the caveat that they didn’t have multiple choice answers to choose from, and they are only ten). The only questions where your most popular answer the wrong one were 6 and 8. (C in Q6, and B in Q8). Thanks for taking part - now look through your workings...

For Year 5 pupils:

1. Mary cut off 2/5 of a piece of string. Later, she cut off another 14 m. The ratio of the length of string remaining to the total length cut off is 1 : 3. What is the length of the remaining string?

A. 5 m
B. 7 m
C. 10 m
D. 14 m
Solution is C. [73 per cent of readers got it right]

Oh Mary! This is how I would have solved it, using equations. Let L be the original length of the string, and R be what is remaining once you have cut the string twice. We know that R = (L x 3/5) – 14m, and that ((L x 2/5) +14) /R = 3, or 2L/5 + 14 = 3R. By substituting the first equation in the second we have 2L/5 + 14 = 9L/5 –42. Which rearranges to:7L/5 = 56, or L = 40. So R = 10m.

Interestingly, the Singapore method of solution is different. It requires us to think more visually about the string: We cut 2/5 of it. Then 14m, and are left with a piece that is a third of the size of what was cut. In other words, we are left with 1/4 of the original length. In order to compare the fractions 2/5 and then 1/4, lets change them to the lowest common denominator, which is 20. So, we cut off 8/20, subtract 14m and are left with 5/20. Let’s now draw the string divided into twentieths:

undefined
The 14m must be 7/20 of the string, which mean each twentieth is 2m. The remaining piece of string is 5/20, i.e 10m

2. The areas of the faces of a rectangular box are 84 cm2, 70 cm2 and 30 cm2. What is the volume of the box?

undefined
Photograph: ISMC
A. 300 cm3
B. 420 cm3
C. 490 cm3
D. 504 cm3
Solution is B. [85 per cent of readers got it right]

First we need to work out the possible side lengths, by seeing which two numbers multiply to be the area of each face. The 84 face could be 1 x 84, 2 x 42, 3 x 28, 4 x 21, 6 x 14 or 7 x 12. The 70 face could be 1 x 70, 2 x 35, 5 x 14 or 7 x 10. The 30 face could be 1 x 30, 2 x 15, 3 x 10 or 5 x 6.

The common factors between 84 and 70 are 1, 2, 7 and 14.
The common factors between 84 and 30 are 1, 2, 3 and 6.
The only way to make 84 with one each of these common factors are 14 from the top line and 6 from the bottom. So the edge bordering the 84 and 70 faces has length 14, and the edge bordering the 84 and 30 edges has length 6. Which means the height must be 30/6, or 70/14 = 5. Thus the volume is 14 x 6 x 5 = 420cm.

3. There are four numbers. If we leave out any one number, the average of the remaining three numbers will be 45, 60, 65 or 70. What is the average of all four numbers?

A. 50
B. 55
C. 60
D. 65
Solution is C. [82 per cent of readers got it right]

If the four numbers are A, B, C and D, then we know that

A + B + C = 45 × 3
A + B + D = 60 × 3
A + C + D = 65 × 3
B + C + D = 70 × 3
Now add them up to get 3A + 3B + 3C + 3D = (45 + 60 + 65 + 70) × 3

Which is A + B + C + D = (45 + 60 + 65 + 70) = 240. So their average is 240/4 = 60

6 0
3 years ago
Jessica has 86 fake tattoos she kept 23 for herself and then shared the rest with 7 of her friends how many tattoos did each fri
Mama L [17]

86-23=63

63/7=9

you're welcome!

. . . . . . . .

6 0
3 years ago
Other questions:
  • Guys what is the perfect square
    8·2 answers
  • an object moves in simple harmonic motion with amplitude 13 m and period 3 minutes. At time t= 0 minutes, its displacement d fro
    13·1 answer
  • 3s+9c=75 <br> 8s+5c=67 <br> S=? C=?
    14·1 answer
  • The expression 3r - 6 can be written as _____. 3(r - 2) 3(r - 6) 3(3r - 6) user: 18 - 2[x (x - 5)] user: simplify 18 - 2[x (x -
    7·1 answer
  • Can someone please do 1,2 and 3 please
    12·1 answer
  • 7/12 ___ 19/36
    15·2 answers
  • When three or more numbers are multiplied, the product is the same regardless of the order of the multiplicands
    12·1 answer
  • A baker bought 4 gallons oficing to decorate cakes. He uses 4 % cups
    13·1 answer
  • Write the missing factor.
    12·2 answers
  • Have even leader = 16.91 oz how many ounces are in 3 leaders
    5·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!