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3 years ago

Results for a 20-point multiple choice math quiz are as follows: 9 students scored a 20,4 students

Mathematics

1 answer:

Ray Of Light [21]3 years ago

3 0

Answer:

18 1/2 or 37/2

Step-by-step explanation:

To calculate the average of something, we add the numbers and divide by the count of those numbers. In this case, we have this as the sum of the numbers:

9 × 20 + 4 × 19 + 3 × 18 + 5 × 17 + 12

And the number of students as the count:

9 + 4 + 3 + 5 + 1

Now to calculate that out:

(9 × 20 + 4 × 19 + 3 × 18 + 5 × 17 + 12)/(9 + 4 + 3 + 5 + 1) ⇒

(180+76+54+85+12)/(9+4+3+5+1) ⇒

407/22 ⇒

37/2⇒

18 1/2

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Write the equation of a line that is perpendicular to y = 7/5 x + 6 y= 5/7and that passes through the point ( 2 , − 6 )

Margarita [4]

Answer:

Equation of a line perpendicular to $y = \frac{7}{5x} + 6$ and passes through the point ( 2 , − 6 ) is 5x – 7y = 4.

Explanation:

Need to write equation of line perpendicular to y = 7/5x + 6 and passes through the point ( 2 , − 6 )

Generic slope intercept form of a line is given by y = mx + c , where m = slope of the line.

On comparing the given slope intercept form of given equation with generic slope intercept form y = mx + c , we can say that for line $y = \frac{7}{5}x + 6$ , slope m = 7/5

Product of slope of perpendicular line is -1 .

Let say slope of required line perpendicular to y = 7/5x + 6 is represented by m1

And as Product of slope of perpendicular line is -1 .

=> $m \times m1 = -1$

=> $\frac{7}{5}\times m1 = -1$

=> $m1 = \frac{-5}{7}$

so now we need to find the equation of a line whose slope is $\frac{-5}{7}$ and passing through (2 , -6).

Equation of line passing through (x1 , y1) and having slope of m is given by

(y – y1) = m (x – x1)

In our case x1 = 2 and y1 = -6 and m = -5/7

Substituting the values in equation of line we get

=> $(y-(-6)) = \frac{-5}{7} (x-2)$

=> $y +6= \frac{-5}{7} x + \frac{10}{7}$

=> 7(y +6) = -5x +10

=> 5x – 7y = 10 – 6

=> 5x – 7y = 4

Hence equation of a line perpendicular to $y = \frac{7}{5x} + 6$ and passes through the point ( 2 , − 6 ) is

5x – 7y = 4.

8 0

4 years ago

I need this TONIGHT!!! Three years ago, Jolene bought $750 worth of stock in a software company. Since then the value of her pur

Paul [167]

Answer:

$A\approx\$880.68$

Step-by-step explanation:

So, we know that Jolene bought an initial $750.

We also know that the purchase is increasing at an average rate of 5 1/2 %or 5.5%. In other words, this is being compounded.

So, we can use the compound interest formula, which is:

$A=P(1+\frac{r}{n})^{nt}$

Where A is the total amount, P is the principal value, r is the rate and n is the number of times compounded per year, and t is the amount of years.

So, substitute 750 for P. 5 1/2% is the same as 5.5% or 0.055 (you move the decimal two places to the left and remove the percent symbol) so substitute this for r. Since it's increasing yearly, n is 1. So, our formula is:

$A=750(1+0.055)^t$

Add:

$A=750(1.055)^t$

Since the stock was bought 3 years ago, the value now is t=3. So, substitute 3 for t and evaluate:

$A=750(1.055)^3$

Evaluate. Use a calculator:

$A\approx\$880.68$

And we're done!

7 0

4 years ago

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Find the missing value so that the two points have a slope of -3/10 (x,-8) and (-5,-5)

rosijanka [135]

Answer:

Step-by-step explanation:

The slope is given by

m = (y2-y1)/(x2-x1)

-3/10 = (-5--8)/(-5-x)

-3/10 = (-5+8)/(-5-x)

Using cross multiplication

-3 (-5-x) = 10*(-5+8)

Simplify

-3(-5-x) =10(3)

Divide by -3

-3/-3(-5-x) =10(3)/-3

-5-x = -10

Add 5 to each side

-5-x+5 = -10+5

-x=-5

Divide by -1

x=5

4 0

3 years ago

A recipe uses 5 cups of water, 3 cups of rice, and 1 cup of black beans. What is the ratio of cups of rice to cups of water?

katovenus [111]

3:5 is the ratio of cups of rice to cups of water.

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3 years ago

What is -2(x-3) how do i answer this question?

-Dominant- [34]

-2(x-3)

= -2x+6

-2*x=-2x and -2*-3=6

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4 years ago

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