HELP ASAP PLS Select the correct answer.
A light bulb's brightness is reduced when placed behind a screen. The amount of visible light produced by the light bulb decreases by 25% with
each additional layer that is added to the screen. With no screen, the light bulb produces 750 lumens. The lumen is a unit for measuring the total
quantity of visible light emitted by a source,
Select the correct equation that can be used to represent the lumens, L, after x screen layers are added.
Answers
Answer:
D. 750(0.75)ˣ
Step-by-step explanation:
Let the new brightness be L'. Since our initial brightness L₀ reduces by 25 %, we have that L' = L₀ - 25% of L₀
L' = L₀ - 0.25L₀
L' = 0.75L₀
Adding the second screen, the new intensity is L" = L' - 25 % of L'
L" = L' - 0.25 L'
L" = 0.75L'.
Since L' = 0.75L₀,
L" = 0.75L' = 0.75(0.75L₀) = 0.75²L₀
Adding the third screen, the new intensity is L"' = L'' - 25 % of L''
L'" = L" - 0.25 L"
L"' = 0.75L".
Since L" = 0.75L' = 0.75²L₀
L"' = 0.75L" = 0.75(0.75²L₀) = 0.75³L₀
So, we see a pattern here.
The intensity after x screens is L = (0.75)ˣL₀
Since L₀ = 750 lumens,
L = 750(0.75)ˣ
Related Questions
Solve the following quadratic by factoring.
x² – 3x – 4=0
List the answers separated by a comma. For example, if you found solutions x = 1 and x = 2, you would enter 1, 2.
Answers
Answer:
4, -1
Step-by-step explanation:
We can reverse the FOIL (First, outside, inside, last) method to break down the equation. The question is asking to solve by factoring so you want to find the right combination of numbers this equation can be broken down into:
x^2 - 3x - 4 = 0
Because we want x squared, x needs to be multiplied by itself, so we can put x in the first slot for each.
(x + or - ?) ( x + or - ?) = 0
Then we need to find numbers that could be added to get -3 and multiplied to get -4. The only set of numbers that works for this is -4 and 1. Note that the sign you put in front of each number has an impact on your answers. With this we get:
(x - 4) (x + 1) = 0
To test that this is equal to the original equation, simply multiply it out using FOIL.
x * x = x^2
x * 1 = x
x * -4 = -4x
-4 * 1 = -4
Putting each component into an equation:
x^2 + x - 4x - 4 = 0
Simplifying:
x^2 - 3x - 4 = 0
Once we are sure it is still the same equation, we find the solutions. We know 0 multiplied by anything equals 0, so to get 0 as the answer, one of the sets in the parentheses must equal 0. (It doesn't matter what the other one is as long is one equals 0)
Therefore, we have 2 solutions, 4, and -1 because if x is 4, 4-4 is 0 which solves the equation, and if x is -1, then -1 + 1 is 0 which also solves the equation.
You can also check your answers by plugging them back into the original equation.
someone pls help me!!
Answers
Answer:
170
Step-by-step explanation:
rititifigkgkrkfjdjfjtjgjgg
Which problem has a greater (bigger) answer? Solve both, choose the one that has the bigger answer and explain (1-2 sentences) how you found your
answer.
1) (2 + 3) (5 + 5)
2)2 + 3 x 5 + 5 =
Answers
= 10 + 15 + 10 + 15 =
= 50
2) 5 • 10 =
= 50
A candy company fills a package of candy with individually wrapped pieces of candy. The number of pieces of candy per package varies because the package is sold by weight. The company wants to estimate the number of pieces per package. Inspectors randomly sample 120 packages of this candy and count the number of pieces in each package. They find that the sample mean number of pieces is 18.72. Assume the population standard deviation of .8735. What is the point estimate of number of pieces per package
Answers
Answer:
The point estimate for the number of pieces per package is of 18.72.
Step-by-step explanation:
Point estimate of a population mean:
The mean of the sample gives an estimate for the population mean.
They find that the sample mean number of pieces is 18.72.
This means that the point estimate for the number of pieces per package is of 18.72.
How do I find the image after it’s been rotated 270 degrees about the point (-2,-1)?
Answers
Answer: (-1, 2)
Step-by-step explanation:
It's a counter-clockwise rotation, that means (x, y) changes to (y, -x).
(-2, -1) ⇒ (-1, -(-2)) ⇒ (-1, 2)
If it's a clockwise rotation, then (x, y) will change to (-y, x)
(-2, -1) ⇒ (-(-1), -2) ⇒ (1, -2)
Lost-time accidents occur in a company at a mean rate of 0.4 per day. What is the probability that the number of lost-time accidents occurring over a period of 9 days will be no more than 5
Answers
Answer:
0.8441
Step-by-step explanation:
This question can be solved by using the microsoft excel command.
we start off by solvingfor the mean rate for 9 days
mean rate = 0.4
for 9 days = 0.4*9 = 3.6
using the excel command,
POISSON (5, 3.6, TRUE)
p(x≤ 5) = 0.8441
so in conclusion 0.8441 is the probability that lost time accidents over 9 days would not be greater than 5.
the attachment is an excel sheet showing the input and the result.
If f(x) = 3 - 4x, find f(1+a)
I am in the need of assistance thank you !
Answers
Step-by-step explanation:
f(x) = 3 - 4x
f(1+a)= 3-4(1+a)
=3-4+4a
=4a-1
The graph of f(x)=x^2 is shown. Compare the graph of f(x) with the graph of d(x)=x^2-26
Answers
A es aaaaaaaaaaaaaaaaaaaaaaa
Examine the two normal probability curves and complete the statements.
The mean of the shorter normal curve is ["equal to", "greater than", "less than"] the mean of the taller normal curve.
The standard deviation of the shorter normal curve is ["less than", "greater than", "equal to"] the standard deviation of the taller normal curve.
The area under the shorter normal curve is ["equal to", "greater than", "less than"] the area under the taller normal curve.
Answers
Answer: hello the two normal probability curves are missing
answer:
a) equal to
b) greater than
c) equal to
Step-by-step explanation:
a) The mean of the shorter normal curve is equal to The mean of the taller normal curve is
b) The standard deviation of the shorter normal curve is greater than the standard deviation of the taller normal curve
c) The area under the shorter normal curve is equal to the area under the taller normal curve
5.
Tax: The property taxes on a house were
$1050. What was the tax rate if the house was
valued at $70,000?
Answers
Answer:
1.5%
Step-by-step explanation:
house value x property tax rate = property taxes
70,000 x property tax rate = 1050
property tax rate = 1050/70000
property tax rate = .015 0r 1.5%
In the word PARADISE,how many pairs are there which have as many letters between them in the word as in the alphabet?
Answers
Answer:
three
P A R
A R A D
A D I S E
P Q R
A B C D
A B C D E
There are three such pairs of letters.
Solve the system of inequalities to decide if the point (-3,2) is part of the solution; y<=-4x-3, +8y>=7
Answers
Answer:
[tex](x,y) = (-3,2)[/tex] is a solution
Step-by-step explanation:
Given
[tex]y \le -4x + 3[/tex]
[tex]x + 8y \ge 7[/tex]
Required
Determine if [tex](x,y) = (-3,2)[/tex] is a solution
[tex]y \le -4x + 3[/tex] becomes
[tex]2 \le -4 * -3 + 3[/tex]
[tex]2 \le 15[/tex] --- this is true
[tex]x + 8y \ge 7[/tex]
[tex]-3+ 8 * 2 \ge 7[/tex]
[tex]13 \ge 7[/tex] --- this is also true
Hence,
[tex](x,y) = (-3,2)[/tex] is a solution
solve the inequality x(x+6) >16
please show steps and interval notation!
Answers
Answer:
x > 2, x < -8
Interval notation:
( -infinity, -8) U (2, infinity)
Step-by-step explanation:
x(x+6) > 16
distribute x into x+6, multiply
x^2 + 6x > 16
bring 16 to left side, subtract
x^2 + 6x - 16 > 0
factors of -16 that add to +6 is -2 and +8
(x - 2)(x + 8) > 0
solve for x:
x < -8, x > 2
Interval notation:
( -infinity, -8) U (2, infinity)
The sum of a number and 2 times its reciprocal is -3
Answers
Answer:
(-2,-1)
Step-by-step explanation:
let the number=x
its reciprocal=1/x
x+2(1/x)=-3
x+2/x=-3
x²+2=-3x
x²+3x+2=0
(x+2)(x+1)=0
x=-2,-1
Please help me quick
Answers
Answer:
I belive it has no x intercepts
it looks weird, but it can be a function. the x-intercept and the y-intercept can also be found in the table above.
to draw a line that can represent a function with these point, we would need to cross y=0 multiple times, so it will have more then one x-intercept.
option A
key takeaway: just draw stuff you find complicated:)
Find the area of the shaded region. Round to the nearest tenth. 11.1m 130°
Area = [ ? ] m²
Answers
The area of the shaded region is 294.5 m².
What is the area of the entire circle?The area of the entire circle is calculated as follows;
A = πr²
where;
r is the radius of the circleA = π ( 11.1² )
A = 387.1 m²
The area of the sector is calculated as follows;
A = ( θ/360 ) πr²
A = ( 130/360 ) x π ( 11.1² )
A = 139.8 m²
The area of the triangle is calculated as follows;
A = ¹/₂ ( sinθ )r²
A = ¹/₂ ( sin 130 ) (11.1²)
A = 47.2 m²
Area of the unshaded region is calculated as;
A' = 139.8 m² - 47.2 m²
A' = 92.6 m²
The area of the shaded region is calculated as follow;
A'' = 387.1 m² - 92.6 m²
A'' = 294.5 m²
Learn more about area of shaded region here: https://brainly.com/question/14989383
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convert 65 kg into gram .
Answers
Answer:
65000
Step-by-step explanation:
65x 1000
1000 because 1kg= 1000
prove that the square of an odd number is always 1 more than a multiple of 4
Answers
Answer:
By these examples you are able to see that the square of an odd number is always 1 more than a multiple of 4.
Step-by-step explanation:
For examples,
Let's consider squares of 3, 11, 25, 37 and 131.
[tex] {3}^{2} = 9[/tex]
8 is a multiple of 4, and 9 is more than 8.
[tex] {11}^{2} = 121[/tex]
120 is a multiple of 4 and 121 is one more than it.
[tex] {25}^{2} = 625[/tex]
624 is a multiple of 4 and 625 is one more than it.
[tex] {37}^{2} = 1369[/tex]
1368 is a multiple of 4 and 1369 is one more than 1368.
[tex] {131}^{2} = 17161[/tex]
17160 is a multiple of 4.
In 2006, there were 160 teachers in College A, and three fourth of them had their own vehicles. In 2007, 20 new teachers came to the school and 6 of them had own vehicles. Calculate the percentage increase in the numbers of teacher who had own vehicles.
Answers
Answer: 5%
Step-by-step explanation:
In 2006, there were 160 teachers in College A, and ¾ of them had their own vehicles, the number of people who had their own vehicles will be:
= 3/4 × 160
= 120
In 2007, 20 new teachers came to the school and 6 of them had own vehicles. This means the number if people with vehicles will be:
= 120 + 6
= 126
The percentage increase will be:
= Increase / Old vehicle owners × 100
= 6/120 × 100
= 1/20 × 100
= 5%
The Percentage increase is 5%.
For a confidence level of 88%, find the critical value for a normally distributed variable. The sample mean is normally distributed if the population standard deviation is known.
Answers
Answer:
z = ± 0.772193214
Step-by-step explanation:
Hence, the critical value for a [tex]88[/tex]% confidence level is [tex]z=1.56[/tex].
What is the standard deviation?
Standard deviation is the degree of dispersion or the scatter of the data points relative to its mean, in descriptive statistics.
It tells how the values are spread across the data sample and it is the measure of the variation of the data points from the mean.
Here given that,
For a confidence level of [tex]88[/tex]%, find the critical value for a normally distributed variable.
Let us assume that the standard normal distribution having a mean is [tex]0[/tex] and the standard deviation is [tex]1[/tex].
As the significance level is [tex]1[/tex] - confidence interval
Confidence interval is [tex]\frac{80}{100}=0.88[/tex]
i.e., [tex]1-0.88=0.12[/tex]
For the two sided confidence interval the confidence level is [tex]0.44[/tex].
Now, the standard normal probability table the critical value for the [tex]88[/tex]% confidence level is [tex]1.56[/tex].
Hence, the critical value for a [tex]88[/tex]% confidence level is [tex]z=1.56[/tex].
To know more about the standard deviation
https://brainly.com/question/13905583
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20 points help please.
Answers
Answer:
-2 is the answer trust me
What is an amount between $2 and $10?
Answers
Answer:
6
Step-by-step explanation:
Helppp me with this ,I will mark brainlest
Answers
2) D (3,-2),(-2,-6),(3,4)
On a coordinate plane, 2 triangles are shown. The first triangle has points A (negative 1, negative 2), B (negative 4, negative 2), C (negative 1, negative 4). The second triangle has points A prime (1, 2), B prime (4, 2), C prime (1, 4). What rule describes the rotation about the origin? (x, y) → How many degrees was the figure rotated about the origin?
Answers
9514 1404 393
Answer:
(x, y) ⇒ (-x, -y)180°Step-by-step explanation:
Each image point has its signs reversed from the pre-image point.
(x, y) ⇒ (-x, -y) . . . . describes the rotation
Rotation from the third quadrant (A) to the first quadrant (A') is a rotation of 180°.
Answer:
3rd and 2nd option
Step-by-step explanation:
There are seven people online and each person uses either a blue, black, or red pen to write while working. How many possible combinations can be made?
A. 49
B. 28
C. 21
D. 10
A S A P!! I DONT WANT MY DAD YELLING AT ME FOR THIS ;^;
Answers
Answer:
21 is the answer for this question may be
Use the following cell phone airport data speeds (Mbps) from a particular network. Find the percentile corresponding to the data speed 6.7 Mbps0.2
0.5
1.1
2.7 0.35.60.51.12.55.00.30.51.22.78.20.30.51.22.79.60.30.51.63.210.60.30.61.63.413.00.30.62.13.614.10.40.72.13.815.10.40.82.34.015.20.4l.O2.44.030.4
Answers
Answer:
The answer is "58th %".
Step-by-step explanation:
2.4 Mbps in the sort data set is the 30th data point. Therefore 29 numbers out of 50 are less than 2.4 Mbps.
[tex]=\frac{29}{50} = 0.58 =58\%\\\\[/tex]
The X-th percent is just the same as x% below the percent and thus 2,4 Mpbs corresponds to a 58th percent.
If you vertically stretch the linear parent function, f(x) = x, by a factor of 5, what is the equation of the new function?
Answers
9514 1404 393
Answer:
f(x) = 5x
Step-by-step explanation:
Vertical stretch is accomplished by multiplying the function value by the stretch factor. f(x) = x is stretched by a factor of 5 by multiplying it by 5:
f(x) = 5x
Answer:
f(x)=5xStep-by-step explanation:
hope it helps much
Ivan is playing a skee-ball game. Different points are awarded depending on which hole the ball goes through. When the ball goes in the smallest hole, it is worth 100 points. When it goes in the bigger hole, it is worth 10 points, and when it does not go in either hole, it is worth 1 point. Ivan earned 352 points in the last game.
Which combination will result in a score greater than his current score?
2 balls in the smallest hole, and 8 balls in the bigger hole
4 balls in the smallest hole, and 6 balls in neither hole
3 balls in the smallest hole, 4 balls in the bigger hole, and 3 balls in neither hole
3 balls in the smallest hole, 3 balls in the bigger hole, and 4 balls in neither hole
Answers
Answer:
B.
Step-by-step explanation:
I don't know for a fact but i think its B. Sorry if I got it wrong.
Explain how to divide a decimal by a decimal
Answers
Answer:
To divide a decimal by another decimal:
Move the decimal point in the divisor to the right until it is a whole number.
Move the decimal point in the dividend to the right by the same number of places as the decimal point was moved to make the divisor a whole number.
Then divide the new dividend by the new divisor
Step-by-step explanation:
see in the example
Find m∠1, m∠2, and m∠4 if m∠3=43°27’.
Answers
Answer:
Since there was a ray drawn from A through C the exterior angle of angle C is angle 1. Any straight line should equal to 180 degrees. Demetria W.
m∠2 = 38
Step-by-step explanation:
