Ask question

Ask question

All categories

2 years ago

7

In a particular classroom, a student who did not study scored 60 points on a test. If that student scored 90 points when studyin

g for three hours, what is the rate of change of his score per hour studied?

1 answer:

Oksanka [162]2 years ago

5 0

30 points over 3 hours equals: 10 points/hr

You might be interested in

I Need Some Help!!!!!!!!!

ehidna [41]

Answer:

median = 50

difference in the quartiles = 45

Step-by-step explanation:

The median amount is the line in the middle of the box

The median is 50

The difference between the upper quartile and the lower quartile is the difference between the right end of the box and the left end of the box

65-20 = 45

4 0

3 years ago

Determine what shape is formed for the given coordinates for ABCD, and then find the perimeter and area as an exact value and ro

Helga [31]

Answer:

Part 1) The shape is a trapezoid

Part 2) The perimeter is $25(4+\sqrt{2})\ units$ or approximately $135.4\ units$

Part 3) The area is $937.5\ units^2$

Step-by-step explanation:

step 1

Plot the figure to better understand the problem

we have

A(-28,2),B(-21,-22),C(27,-8),D(-4,9)

using a graphing tool

The shape is a trapezoid

see the attached figure

step 2

Find the perimeter

we know that

The perimeter of the trapezoid is equal to

$P=AB+BC+CD+AD$

the formula to calculate the distance between two points is equal to

$d=\sqrt{(y2-y1)^{2}+(x2-x1)^{2}}$

Find the distance AB

we have

A(-28,2),B(-21,-22)

substitute in the formula

$d=\sqrt{(-22-2)^{2}+(-21+28)^{2}}$

$d=\sqrt{(-24)^{2}+(7)^{2}}$

$d=\sqrt{625}$

$d_A_B=25\ units$

Find the distance BC

we have

B(-21,-22),C(27,-8)

substitute in the formula

$d=\sqrt{(-8+22)^{2}+(27+21)^{2}}$

$d=\sqrt{(14)^{2}+(48)^{2}}$

$d=\sqrt{2,500}$

$d_B_C=50\ units$

Find the distance CD

we have

C(27,-8),D(-4,9)

substitute in the formula

$d=\sqrt{(9+8)^{2}+(-4-27)^{2}}$

$d=\sqrt{(17)^{2}+(-31)^{2}}$

$d=\sqrt{1,250}$

$d_C_D=25\sqrt{2}\ units$

Find the distance AD

we have

A(-28,2),D(-4,9)

substitute in the formula

$d=\sqrt{(9-2)^{2}+(-4+28)^{2}}$

$d=\sqrt{(7)^{2}+(24)^{2}}$

$d=\sqrt{625}$

$d_A_D=25\ units$

Find the perimeter

$P=25+50+25\sqrt{2}+25$

$P=(100+25\sqrt{2})\ units$

simplify

$P=25(4+\sqrt{2})\ units$ ----> exact value

$P=135.4\ units$

therefore

The perimeter is $25(4+\sqrt{2})\ units$ or approximately $135.4\ units$

step 3

Find the area

The area of trapezoid is equal to

$A=\frac{1}{2}[BC+AD]AB$

substitute the given values

$A=\frac{1}{2}[50+25]25=937.5\ units^2$

4 0

3 years ago

poizon [28]

The answer is -4,0 4,8 because u would solve for one variable in one of the equations and then substitute the result into the other

5 0

2 years ago

The weight of a piece of raw silk that is 100 yards long by 1.25 yards wide (standard width) is about 38 pounds. The weight of a

butalik [34]

The total weight of the two pieces together is 6 pounds.

<h3>How much would the two pieces weigh together?</h3>

A piece of raw silk that is 100 yards long by 1.25 yards wide weights 38lb.

Then, a piece that is 12.5 yards long (and still 1.25 yards wide) will weight:

M = (12.5/100)*38lb = 4.75 lb

And a piece of habotai silk that is 100 yards long by 1.25 yards wide weights 12lb.

Then, a piece that is 12.5 yards long will weigh:

M' = (12.5/100)*12lb = 1.5 lb

If we add these two, we get a total weight of:

M + M' = 4.5lb + 1.5lb = 6lb

The total weight of the two pieces together is 6 pounds.

If you want to learn more about weight:

brainly.com/question/11408596

#SPJ1

5 0

1 year ago

Sarah is doing research on the average age of first-year resident physicians. She wants her estimate to be accurate to within 1

WINSTONCH [101]

Answer: The number of first-year residents she must survey to be 95% confident= 263

Step-by-step explanation:

When population standard deviation ( $\sigma$ ) is known and margin of error(E) is given, then the minimum sample size (n) is given by :-

$n=(\dfrac{z^*\sigma}{E})^2$ , z* = Two-tailed critical value for the given confidence interval.

For 95% confidence level , z* = 1.96

As, $\sigma$ = 8.265, E = 1

So, $n= (\dfrac{1.96\times8.265}{1})^2 =(16.1994)^2\\\\= 262.42056036\approx263\ \ \ [\text{Rounded to the next integer}]$

Hence, the number of first-year residents she must survey to be 95% confident= 263

7 0

3 years ago