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alexira [117]
3 years ago
14

Assume that advanced students average 93% on an achievement test and regular students averaged 75%. If 100 advanced students and

300 regular students took the test, what would you expect the average to be? How many of each kind of student would be needed to get a group of 90 students who average 87% on the test? Please include work/explaination, I along with a few of my classmates are confused by this problem. We are in a chapter about systems of equations.
Mathematics
1 answer:
Lemur [1.5K]3 years ago
7 0
Average (mean) = (sum of all the data) / (# of data)

sum of all the data = (average)(# of data)

Thus for 100 students with an average of 93,
sum of all data = (93)(100) = 9300

and for 300 students with an average of 75,
sum of all data = (75)(300) = 22500

Therefore you would expect the overall average to be
(9300 + 22500) / (100 + 300) = 79.5 %

Now if there are x # of advanced students and y # of regular students, then

x + y = 90 (total # of students) and 93x + 75y = 87(x + y) (overall average)

The second equation can be simplified to x - 2y = 0

Subtracting the two equations yields

x = 60 and y = 90

Therefore you would need 60 advanced and 30 regular students.
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Step-by-step explanation:

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Suppose you were given $800 from your uncle. You deposited that money in a bank and added $55 per month. Write an algebraic expr
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800+55x


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The school is located where Wilson Street and Green Street intersect. Which ordered
blondinia [14]

(5,3) is the answer for the current question

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2 years ago
Determine the type of correlation that exists in the given data set. Age (years) 23 45 39 74 63 52 59 28 35 11 26 49 IQ 76 82 11
Lyrx [107]

Answer:

B -0.104

Step-by-step explanation:

Step 1: Write the formula for correlation

r =    total xy

√Total x² x Total y²

Step 2: Make a table to calculate all values

Table is attached in the picture below

Step 3 : Solve

Mean of X = Total X/ Total number of X

                  = 507/12

                  = 106.33

Mean of Y = Total Y/ Total number of Y

                  = 1276/ 12  

                  = 42.25

r =    total xy

√Total x² x Total y²

r = -352.05/ √3656.25 x 3122.66698

r = -0.104

-0.104 is negative

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6 0
3 years ago
Read 2 more answers
4/5G + 42 = 2.8G + 18<br> Plz solve with an explanation
inysia [295]

Answer:

12

Step-by-step explanation:

Simplify  \frac{4}{5}G

​5

​

​4

​​ G  to  \frac{4G}{5}

​5

​

​4G

​​ .

\frac{4G}{5}+42=2.8G+18

​5

​

​4G

​​ +42=2.8G+18

Multiply both sides by 5.

4g + 210 = 14g + 90

Simplify  

 14G + 90 - 4G to 10G + 90

Subtract 90 from both sides.

210-90=10G210−90=10G

Simplify  210-90210−90  to  120120.

120=10G120=10G

Divide both sides by 1010.

\frac{120}{10}=G

​10

​

​120

​​ =G

Simplify  \frac{120}{10}

​10

​

​120

​​   to  1212.

12=G12=G

Switch sides.

G=12G=12

SORRY ABOUT ALL THIS WORK...

3 0
2 years ago
Read 2 more answers
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