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Sandra's scores on the first 4 tests were 87%, 92%, 76%,and 89%. What is the minimum score she needs to make on the fifth test s

sergejj [24]

Answer:

Sandra need to score at least 56% in her fifth test so that her average is 80%.

Step-by-step explanation:

Given:

First 4 test scores = 87%, 92%, 76%,89%

Average targeted = 80%

We need to find the minimum score she needs to make on fifth test to achieve average of at least 80%.

Solution:

Let the minimum score she needs to make in fifth test be 'x'.

Total number of test = 5

Now we know that;

Average is equal to sum of all the scores in the test divided by number of test.

framing in equation form we get;

$\frac{87+92+76+89+x}{5}=80$

Multiplying both side by 5 we get;

$\frac{344+x}{5}\times 5=80\times 5\\\\344+x=400$

Subtracting both side by 344 we get;

$344+x-344=400-344\\\\x=56\%$

Hence Sandra need to score at least 56% in her fifth test so that her average is 80%.

5 0

3 years ago

Can you step by step solve 20x+12=4x-16

Murljashka [212]

Answer:

x = - $\frac{7}{4}$

Step-by-step explanation:

Given

20x + 12 = 4x - 16 ( subtract 4x from both sides )

16x + 12 = - 16 ( subtract 12 from both sides )

16x = - 28 ( divide both sides by 16 )

x = $\frac{-28}{16}$ = - $\frac{7}{4}$ [ = - 1.75 ]

4 0

3 years ago

a grandmother says her grandson is two years older than her granddaughter and that together, they are at least 12 years old. how

vfiekz [6]

Hello There!

As for this problem, we would have to set up an equation in order to determine the missing age. We would do this because we want to find the missing age and by setting up an equation it will help find the age easier, as opposed to manually calculating it. With that said, let's begin to solve.

First, we would create an equation based on what the question says, which would look as:

x + x + 2 = 12

2x + 2 = 12

Subtract two from both sides.

2x = 10

The grand daughter is 5 years old and since the grandson is two years older he is 7.

Thus,

The age of the granddaughter is 5

The age of the grandson is 7

7 0

3 years ago

Find the intersection point between the lines of equations: 2x-y+6=0 and 2x+3y-6=0