Answer:
The number of rainfalls is [tex]n =96[/tex]
The answer to the second question is no it will not be valid this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the pH reading) from one rainfall will make the experiment invalid.
Step-by-step explanation:
from the question we are told that
The standard deviation is [tex]\sigma = 0.5[/tex]
The margin of error is [tex]E = 0.1[/tex]
Given that the confidence level is 95% then we can evaluate the level of significance as
[tex]\alpha = 100 - 95[/tex]
[tex]\alpha = 5 \%[/tex]
[tex]\alpha =0.05[/tex]
Next we will obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table , the value is [tex]Z_{\frac{\alpha }{2} } = 1.96[/tex]
Generally the sample size is mathematically represented as
[tex]n = [\frac{Z_{\frac{\alpha }{2} * \sigma }}{ E} ]^2[/tex]
substituting values
[tex]n = [\frac{1.96 * 0.5 }{ 0.1} ]^2[/tex]
[tex]n =96[/tex]
The answer to the second question is no the validity is null this because from the question we are told that the experiment require one pH reading per rainfall so getting multiply specimens(used for the pH reading) from one rainfall will make the experiment invalid
Simple geometry please help
Find KL. Round to the nearest hundredth.
Answer:
KL ≈ 1.94
Step-by-step explanation:
Using the cosine ratio in the right triangle
cos48° = [tex]\frac{adjacent}{hypotenuse}[/tex] = [tex]\frac{JL}{KL}[/tex] = [tex]\frac{1.3}{KL}[/tex] ( multiply both sides by KL )
KL × cos48° = 1.3 ( divide both sides by cos48° )
KL = [tex]\frac{1.3}{cos48}[/tex] ≈ 1.94 ( to the nearest hundredth )
How do you find the equation of a parabola given the coordinates?
Answer:
the general equation of parabola is,
y=ax²+bx+c,
you put the given points in the equation since they will satisfy the equation, after that you should get three equations with only a,b,c in them, solve them for a,b,c and find their values, then just put the values in the main equation, which is, y=ax²+bx+c, that's all you have to do
Simplify, write without exponents.
[tex]2*4^{2} *(128\frac{1}{4})[/tex]
[tex]_\sqrt[_]{_}[/tex]
a.) 8
b.) 20
c.) 2
d.) 64
e.) 4
f.) 16
it is helpful to you
Please answer this question
A sandman earns a commission of 26%. One week he had sales of $24400. Find the commission for the week.
Answer:
6344
Step-by-step explanation:
Find 26% of 24400
24400 * 26%
24400 * .26
6344
Tessa’s employee benefits include family health care coverage. She contributes 18% of the cost. Tessa gets paid biweekly and $108.00 is taken out of each paycheck for family health care coverage. How much does her employer contribute annually for the family coverage? Clearly show your work.
The answer is $12792
Explanation:
It is known Tessa pays $108.00 to contribute to family coverage every two weeks and this represents 18% of the total payment. This implies the employer pays the 82% missing (100% - 18% = 82%). Additionally, with this information, it is possible to know the amount the employer has to pay every two weeks that represents 82%. The process is shown below:
1. Write the values you know and use x to represent the value you need to find
108 = 18
x = 82
3. Cross multiply
x 18 = 8856
4. Find the value of x by solving this simple equation
x = 8856 ÷ 18
x = 492 - Amount the employer pays every two weeks for Tessa's family coverage
Now that we know the money the employer pays every two weeks, it is possible to calculate the annual amount of money. Follow the process below.
1. Consider one year has a total of 52 weeks and divide this number of weeks by 2 because the payment for the family coverage occurs every 2 weeks
52 ÷ 2 = 26
2. Finally, multiply the money paid by the employer every two weeks by 26
26 weeks x $492 = $12792- This is the total the employer pays annually
The measure of one of the small angles of a right triangle is 45 less than twice the measure of the other small angle. Find the measure of both angles.
Answer:
Step-by-step explanation:
A right triangle has one right angle and two acute angles.
A and B are the acute angles.
A+B = 90°
One acute angle is 45 less than twice the other acute angle.
A = 2B-45°
(2B-45°) + B = 90°
3B = 135°
B = 45°
A = 45°
Please Help quick!!! What is the value of a missing angle?
Answer:
69
Step-by-step explanation:
90-21=69
Answer:
69 degrees
Step-by-step explanation:
The full angle = 90 degrees.
One part of the full angle = 21 degrees
The other part of the full angle = x
Other angle = 90 - 21
=> the other angle = 69 degrees
if the current time is 10:35 how long until it turns 3:15
Answer:
10:35-3:15
5 hoursIn determining your group’s estimate, what mathematical model of a tennis ball did you use? What model of the classroom did you use? Did you make other simplification or assumptions?
Answer:
bro ur question is not understandable
Match each polynomial on the left with its two factors on the right.
Answer:
Hello
Step-by-step explanation:
[tex]Formula: \\\\\boxed{\Large a^3\pm b^3=(a \pm b)(a^2 \mp ab+b^2)}\\\\8x^3+1=(2x)^3+1^3=(2x+1)(4x^2-2x+1)\\\\8x^3-1=(2x)^3-1^3=(2x-1)(4x^2+2x+1)\\[/tex]
The factors of the expression 8x³ + 1 and 8x³ - 1³ will be (2x + 1) & (4x² – 2x + 1) and (2x – 1) & (4x² + 2x + 1), respectively.
What is a polynomial?A polynomial expression is an algebraic expression with variables and coefficients. Unknown variables are what they're termed. We can use addition, subtraction, and other mathematical operations. However, a variable is not divisible.
The expression is given below.
8x³ + 1 and 8x³ - 1³
(2x)³ + 1³ and (2x)³ - 1³
We know that the formula is given as,
a³ + b³ = (a + b) (a² – ab + b²)
a³ – b³ = (a – b) (a² + ab + b²)
Then the expression is written as,
(2x)³ + 1³ = (2x + 1) [(2x)² – 2x + 1²]
(2x)³ + 1³ = (2x + 1) (4x² – 2x + 1)
(2x)³ – 1³ = (2x – 1) [(2x)² + 2x + 1²]
(2x)³ – 1³ = (2x – 1) (4x² + 2x + 1)
The factors of the expression 8x³ + 1 and 8x³ - 1³ will be (2x + 1) & (4x² – 2x + 1) and (2x – 1) & (4x² + 2x + 1), respectively.
More about the polynomial link is given below.
https://brainly.com/question/17822016
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The graph shows the weight of a jar when filled with different numbers of marbles.
What does the y-intercept represent?
A) The weight of the marbles without the jar.
B) The weight of the jar without the marbles.
C) The weight of one marble and the jar.
D) The unit rate for each marble added.
Answer:
B
Step-by-step explanation:
The weight of the jar depends on the number of marbles in it, therefore the weight is the dependent variable (y) and the number of marbles is the independent variable (x). The y-intercept is when x = 0 and since the number of marbles is x, the answer is that the y-intercept represents the weight of the jar without the marbles.
Which best describes the relationship between the lines with equations x + 8y = -1 and —8x +y = -1?
Answer:
the lines are perpdicular if you were to get some graph paper and graph u would see
A triangle has a base that is increasing at a rate of 18 mm per minute with the height being held constant. What is the rate of change of the area of the triangle if the height is 7 mm
Answer:
63mm/minStep-by-step explanation:
Area of a triangle = 1/2 * base * height
A = 1/2bh
Rate of change of area is expresssed as dA/dt = dA/db * db/bt
db/dt is the rate at which the base is increasing.
Given db/dt = 18mm/min
A = 1/2*7b
A = 7b/2
dA/db = 7/2
The rate at which the area is changing dA/dt = dA/db * db/bt
dA/dt = 7/2 * 18
dA/dt = 7*9
dA/dt = 63mm/min
Hence the rate at which the area of the triangle is changing is 63mm/min
Find the distance between (-8, 4) and (-8, -2).
10 units
2 units
6 units
8 units
Answer:
10
Step-by-step explanation:
A 10-ft ladder, whose base is sitting on level ground, is leaning at an angle against a vertical wall when its base starts to slide away from the vertical wall. When the base of the ladder is 6 ft away from the bottom of the vertical wall, the base is sliding away at a rate of 4 ft/sec. At what rate is the vertical distance from the top of the ladder to the ground changing at this moment?
Answer:
2.5/ft per sec
Step-by-step explanation:
its vertica.
The height of the ladder is decreasing at a rate of 24 ft/sec.
What is the Pythagorean theorem?Pythagorean theorem states that for a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.
We can apply this theorem only in a right triangle.
Example:
The hypotenuse side of a triangle with the two sides as 4 cm and 3 cm.
Hypotenuse side = √(4² + 3²) = √(16 + 9) = √25 = 5 cm
We have,
Let's denote the distance between the base of the ladder and the wall by x.
The length of the ladder = L.
Now,
L = 10 ft
dx/dt = 4 ft/sec
x = 6 ft.
The rate of change of the height of the ladder with respect to time.
Using the Pythagorean theorem, we have:
L² = x² + y²
Differentiating both sides with respect to time t, we get:
2L (dL/dt) = 2x(dx/dt) + 2y(dy/dt)
Substituting L = 10 ft, x = 6 ft, and dx/dt = 4 ft/sec.
20(dL/dt) = 12(4) + 2y(dy/dt)
Simplifying and solving for dy/dt.
dy/dt = (20/2y)(dL/dt) - 24
Now,
The height of the ladder.
Using the Pythagorean theorem again, we have:
y² = L² - x²
= 100 - 36
= 64
y = 8
Now,
Substituting y = 8 ft, dL/dt = 0
(since the length of the ladder is constant), and dx/dt = 4 ft/sec.
dy/dt
= (20/2(8))(0) - 24
= -24 ft/sec
Therefore,
The height of the ladder is decreasing at a rate of 24 ft/sec.
Learn more about the Pythagorean theorem here:
https://brainly.com/question/14930619
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26) What is the perimeter of a rectangle whose
lengths are 9x + 5 and widths are 7x + 2?
Answer:
32х+14
Step-by-step explanation:
[tex]2(9x + 5 + 7x + 2) \\ 18x + 10 + 14x + 4 \\ 32x + 14[/tex]
Answer:
32x + 14
Step-by-step explanation:
The opposite sides of a rectangle are equal, so
perimeter = 2(9x + 5) + 2(7x + 2) ← distribute parenthesis
= 18x + 10 + 14x + 4 ← collect like terms
= 32x + 14
What effect will replacing x with (x - 4) have on the graph of the equation y = (x - 3) ^ 2
A. Slides the graph 4 units up
B. Slides the graph 7 units down
C. Slides the graph 4 units right
D. Slides the graph 1 units
Answer:
C)slides graph 4 units to the right
_______% of 44 = 22
Answer:
50%
Step-by-step explanation:
22 is half of 44.
So, this means 50% of 44 is 22.
Write the point-slope form of an equation of the line through the points (-1, 4) and (-2, 2).
Answer:
Point-slope form: y-4=2(x+1)
Slope intercept form: y=2x+6
I hope this helps!
Answer:
[tex]y-4=2(x+1)[/tex]
Step-by-step explanation:
Point-slope form is equal to
[tex]y-y_1=m(x-x_1)[/tex]
where y and y1 are the known y coordinates of two points on the line, and x and x1 are the known x coordinates of two points on the line. All we need now is m, which is the slope:
[tex]4-2=m(-1-(-2))[/tex]
We can simplify negative one minus negative two as positive 1.
[tex]4-2=m(1)[/tex]
4 minus 2 is 2, so m times 1 is 2. That means m is 2.
Now, we have the slope, so we can convert to point-slope form using one of the two points. Let's use (-1, 4). We can plug those values in for x1 and y1:
[tex]y-4=2(x+1)[/tex]
what is the product of .4 x .38
Answer:
0.152
Step-by-step explanation:
0.4 × 0.38
→ Multiply 0.4 by 10
0.4 × 10 = 4
→ Multiply 0.38 by 100
38
→ Multiply the 2 answers together
4 × 38 = 152
→ Divide by the answer by 1000
152 ÷ 1000 = 0.152
Which expression is equivalent to x+y+x+y+3(y+5)
Answer:
2x + 5y + 15
Step-by-step explanation:
add like terms
(x+x) + (y+y)+3y+15
2x+2y+3y+15
2x + 5y + 15
i hope this helps!
Jack’s backpack weighs 15 pounds. Fernando’s backpack weighs less than Jack’s. Which graph shows how much Fernando’s backpack can weigh?
Answer:
A
Step-by-step explanation:
c and d out of the question
b has its circle filled in meaning it could be 15lbs, which it's not
A correct answer by default
Answer:b
Step-by-step explanation: it has a filled in diamond which mean it's that...
you write a short story, but you want to make sure your work is protected before you post it online. what should you do to help protect your copyright?
Answer:
Hey there!
Here are a few steps:
Make sure your work is properly marked, because then it will be protected under law.
Register your work.
Keep or register supporting evidence.
Let me know if this helps :)
Given f(x)=x^2 + x - 2, find the roots of g(x)=3f (-2x). Hint: Use the mapping rule.
[tex]f(x) = {x}^{2} + x - 2 \\ f( - 2x) = ( - 2x) ^{2} + ( - 2x) - 2 \\ = 4 {x}^{2} - 2x - 2 \\ \\ g(x) = 3f( - 2x) \\ g(x) = 3(4 {x}^{2} - 2x - 2) \\ = 12 {x}^{2} - 6x - 6 \\ = 6(2x + 1)(x - 1) \\ \\ g(x) = \sqrt{3f( - 2x)} \\ = \sqrt{3(4 {x}^{2} - 2x - 2)} \\ = \sqrt{12 {x}^{2} - 6x - 6} \\ = \sqrt{6(2x + 1)(x - 1)} \\ x = - \frac{1}{2} ,1[/tex]
From what I understood from the question I answered, I'm not sure about it , I hope this helps you ^_^
5^2x+4×5^-x+1-125=0
Answer:
Take 5^x as y.
Now the question becomes a simple equation.
y + 20y - 125 = 0.
21y = 125.
Thus, y = 125/21.
Now resubstituting we get,
5^x = 125 /21.
Taking log on both sides,
xlog5 = log 125 - log 21
x = (log125/log5) - (log21/log 5)
x= 3- 1.89
Line L has a slope of 1/2 . The line through which of the following pair of points is perpendicular to L?
The line which crosses through L must have an intersect point with L to become perpendicular.
Gien slope is positive 1/2.
What is a straight line graph?The graph follows a straight line equation shows a straight line graph.equation of a straight line is y=mx+cy represents vertical line y-axis.x represents the horizontal line x-axis. m is the slope of the lineslope(m)=tan∅=y axis/x axis.
c represents y-intercepts (it is the point at which the line cuts on the y-axis)Straight line graphs show a linear relationship between the x and y values.
Learn more about the straight lines here:-https://brainly.com/question/14323743
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Arborist 96% positive tree has a disease, 97% trees do not have disease. Probability of a false positive?
Answer:
Step-by-step explanation:
the probability that the test result is positive (suggesting the person has the disease), given that the person does not have the disease, is only 2 percent; the probability that the test result is negative (suggesting the person does not have the disease), given that the person has the disease, is only 1 percent.
A cylinder shaped can needs to be constructed to hold 550 cubic centimeters of soup. The material for the sides of the can costs 0.04 cents per square centimeter. The material for the top and bottom of the can need to be thicker, and costs 0.07 cents per square centimeter. Find the dimensions for the can that will minimize production cost.
9514 1404 393
Answer:
radius: 3.685 cmheight: 12.896 cmStep-by-step explanation:
The cost of the ends of the can will be ...
c1 = 0.07(2πr²)
The cost of the side of the can will be ...
c2 = 0.04(2πrh)
The volume of the can will be ...
v = πr²h
We want the derivative of the total cost to be zero, and we want the volume to be 550 cm³. We can take the derivatives of both equations to find a relation between r and h.
d(c1 +c2) = 0.28πr·dr +0.08π(h·dr +r·dh) = 0
d(v) = 2πrh·dr +πr²·dh = 0
Solving the first equation for dh/dr gives ...
dh/dr = -π(0.28r +0.08h)/(π(0.08r)) = -(7r+2h)/(2r)
Solving the second equation for dh/dr gives ...
dh/dr = -2πrh/(πr²) = -2h/r
Equating these expressions, we get ...
-(7r +2h)/(2r) = -2h/r
7r +2h = 4h . . . . . . . multiply by -2r
h = 7/2r . . . . . . . . . . subtract 2h, divide by 2
__
Now, we can find the can dimensions from the volume equation.
550 = πr²(7/2r)
r³ = 1100/(7π)
r ≈ ∛50.02 ≈ 3.685 . . . . . cm
h = 7/2(3.685 cm) = 12.896 cm
The can cost will be a minimum when the radius is 3.685 cm and the height is 12.896 cm.
_____
Additional comment
You may notice that the ratio of height to diameter is the same as the ratio of end cost to side cost: 7/4. This is the generic solution to this sort of problem.
Please Help Me I will probably post more like this as its the only thing really that's holding me back from passing 5th grade on khan academy math!!
Answer:
330 cm^3
Step-by-step explanation:
Volume of figure=Volume of the cuboid+Volume of the other cuboid
Volume of figure=240+90=330