Answer: If Percentage decrease % = 20%, (1 - Percentage decrease %) = 1 - 20% = 100/100 - 20/100 = 80/100 = 0.8 => Percentage decreased number = 0.8 × Initial value
Step-by-step explanation: Number 100 decreased by 20% (20 percent) of its value (percentage decrease) and calculated absolute change (actual difference)
Please help! Steps if possible: If n=31, ¯x (x-bar)=41, and s=12, construct a confidence interval at a 90% confidence level. Assume the data came from a normally distributed population.
Give your answers to one decimal place.
decimal place.
________ < μ < _______
Answer: [tex]\boldsymbol{37.5} < \mu < \boldsymbol{44.5}[/tex]
===========================================================
Explanation:
At a 90% confidence level, the z critical value is roughly z = 1.645. Use a reference table or a calculator to determine this. Despite not knowing what sigma is, we can use a z interval here because n > 30. If the sample size n was smaller than 30, then we'd have to use a T distribution instead.
We'll plug that z value, along with the other given values, into the formula for the lower boundary L of the confidence interval.
[tex]L = \text{lower boundary}\\\\L = \overline{x} - z*\frac{s}{\sqrt{n}}\\\\L = 41 - 1.645*\frac{12}{\sqrt{31}}\\\\L = 41 - 3.545\\\\L = 37.455\\\\L = 37.5\\\\[/tex]
This value is approximate.
Do the same for the upper boundary as well
[tex]U = \text{upper boundary}\\\\U = \overline{x} + z*\frac{s}{\sqrt{n}}\\\\U = 41 + 1.645*\frac{12}{\sqrt{31}}\\\\U = 41 + 3.545\\\\U = 44.545\\\\U = 44.5\\\\[/tex]
This value is also approximate.
We have 90% confidence that the population mean [tex]\mu[/tex] (greek letter mu) is somewhere between L = 37.5 and U = 44.5
Therefore, we would write the 90% confidence interval as [tex]\boldsymbol{37.5} < \mu < \boldsymbol{44.5}[/tex]
This is the same as writing the confidence interval in the form [tex](\boldsymbol{37.5} , \boldsymbol{44.5})[/tex]. Both forms are two different ways to say the same thing. The first form being [tex]L < \mu < U[/tex] while the second form is [tex](L,U)[/tex].
Side note: The value 3.545 calculated earlier is the approximate margin of error.
Solve the equation for B. PLEASE SHOW YOUR WORK.
2(B + 3.5 - B = -3(6 - 2B)
9514 1404 393
Answer:
B = 5
Step-by-step explanation:
The given equation has mismatched parentheses. We assume the intent is ...
2(b +3.5) -b = -3(6 -2b)
Eliminating parentheses, we have ...
2b +7 -b = -18 +6b
25 = 5b . . . . . . . . . . . add 18-b to both sides and collect terms
b = 5 . . . . . . . . . . . . divide both sides by 5
g A pipe of negligible diameter is to be carried horizontally around a corner from a hallway 8 ft wide into a hallway 4 ft wide. What is the longest length that the pipe can be
The length of the longest pipe that can be carried horizontally is given by the minimum value of the function of the length of the pipe.
The longest length that the pipe can be is approximately 16.648 feet.
Reasons:
The length of the pipe, L
Width of the first hallway = 8 ft.
The width of the second hallway = 4 ft.
We have;
(L - a)·sin(θ) = 8
a·cos(θ) = 4
Therefore;
L - a = 8·csc(θ)
a = 4·sec(θ)
L(θ) = 8·csc(θ) + 4·sec(θ)
At the minimum length, we have;
L'(θ) = 4·sec(θ)·tan(θ) - 8·csc(θ)·cot(θ) = 0
4·sec(θ)·tan(θ) = 8·csc(θ)·cot(θ)
Therefore;
[tex]\displaystyle \frac{sec(\theta) \cdot tan(\theta)}{csc(\theta) \cdot cot(\theta)} = \frac{sin(\theta) \cdot tan(\theta) \cdot tan(\theta) }{cos(\theta) } =tan^3(\theta) = \frac{8}{4}[/tex]
[tex]\displaystyle tan(\theta) =\sqrt[3]{\frac{8}{4} } ={\sqrt[3]{2} }[/tex]
θ = arctan([tex]\sqrt[3]{2}[/tex]) ≈ 51.56°
a = 4×sec(arctan([tex]\sqrt[3]{2}[/tex]))
a ≈ 6.434
L = 8·csc(θ) + a = 8 × csc(arctan([tex]\sqrt[3]{2}[/tex])) + 4×sec(arctan([tex]\sqrt[3]{2}[/tex])) ≈ 16.648
The longest length that the pipe can be, L ≈ 16.648 ft.
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The longest length of the pipe is an illustration of trigonometry functions
The longest length of the pipe is 16.64 ft
The widths of the hallways are given as:
[tex]\mathbf{w_1 = 8}[/tex]
[tex]\mathbf{w_2 = 4}[/tex]
See attachment for the diagram that represents the scenario
From the diagram, we have:
[tex]\mathbf{sin(\theta) = \frac 4x}[/tex]
[tex]\mathbf{cos(\theta) = \frac 8y}[/tex]
Make x and y the subject
[tex]\mathbf{x = \frac 4{sin(\theta)}}[/tex]
[tex]\mathbf{y = \frac 8{cos(\theta)}}[/tex]
Where, the total length (L) of the pipe is:
[tex]\mathbf{L = x + y}[/tex]
So, we have:
[tex]\mathbf{L = \frac 4{sin(\theta)} + \frac 8{cos(\theta)}}[/tex]
Differentiate
[tex]\mathbf{L' = -\frac{4cos(\theta)}{sin^2(\theta)} + \frac{8sin(\theta)}{cos^2(\theta)}}[/tex]
Set to 0
[tex]\mathbf{-\frac{4cos(\theta)}{sin^2(\theta)} + \frac{8sin(\theta)}{cos^2(\theta)} = 0}[/tex]
Rewrite as:
[tex]\mathbf{\frac{4cos(\theta)}{sin^2(\theta)} = \frac{8sin(\theta)}{cos^2(\theta)}}[/tex]
Divide through by 4
[tex]\mathbf{\frac{cos(\theta)}{sin^2(\theta)} = \frac{2sin(\theta)}{cos^2(\theta)}}[/tex]
Cross multiply
[tex]\mathbf{2sin^3(\theta) = cos^3(\theta)}[/tex]
Divide both sides by [tex]\mathbf{2cos^3(\theta)}[/tex]
[tex]\mathbf{tan^3(\theta) = \frac 12}[/tex]
Take cube roots of both sides
[tex]\mathbf{tan(\theta) = \sqrt[3]{\frac 12}}[/tex]
[tex]\mathbf{tan(\theta) = 0.7937}[/tex]
Take arc tan of both sides
[tex]\mathbf{\theta = tan^{-1}(0.7937)}[/tex]
[tex]\mathbf{\theta = 38.4}[/tex]
Substitute [tex]\mathbf{\theta = 38.4}[/tex] in [tex]\mathbf{L = \frac 4{sin(\theta)} + \frac 8{cos(\theta)}}[/tex]
[tex]\mathbf{L = \frac 4{sin(38.4)} + \frac 8{cos(38.4)}}[/tex]
Evaluate
[tex]\mathbf{L = 6.43+ 10.21}}[/tex]
[tex]\mathbf{L = 16.64}}[/tex]
Hence, the longest length of the pipe is 16.64 ft
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someone help me on these 2 questions asap! 50 points!!
Step-by-step explanation:
earbuds
we have a 1in : 0.2in scale of drawing to reality.
0.2 = 2/10 = 1/5
so, 1in in the drawing is actually 1/5in in reality.
how long are the 4in in the drawing ?
well, 4 times the 1in thing.
4×1/5 = 4/5 = 0.8in long
again the similar triangles
similar triangles means that each pair of corresponding lines (sides, heights, ...) in the triangles follows the same scaling factor for the length.
so, what do I need to multiply the side of the large triangle with to get the corresponding side length of the small triangle ?
27 × x = 9
x = 9/27 = 1/3
and that is the scale factor.
Richard and Teo have a combined age of 36 Richard is 6 years older than twice Teo's age. How old are Richard and Teo?
Richard is years old, and Teo is years old.
(Type whole numbers.)
Answer:
Richard is twenty-six and Teo is ten.
Step-by-step explanation:
Let x = Richard's age and y = Teo's age
x = 2y + 6
(2y + 6) + y = 36
3y + 6 = 36
-6 -6
3y = 30
y = 10
x = 2(10) + 6
x = 20 + 6
x = 26
Richard is 26
Teo is 10
The circumference (C) of a swimming pool is 47 feet. Which formula can you use to find the radius (r) if you know that C = 2πr ?
Answer:
The answer is 7.48 or 7.5
Step-by-step explanation:
If the circumference is C which is equal to 47 feet, what you have to do is divide it by pi, or 3.14 for an estimate. After that, you'll get the diameter and then divide it by 2. Now you have your radius.
passes through (2,-3) with a slope of -9/2
Answer:
y = — 9/2x + 6
Step-by-step explanation:
m= —9/2
y — y1 = m (x — x1)
y + 3 = —9/2 (x — 2)
y = — 9/2x + 6
Determine whether the inverse of F(x) is a function.
what is the diameter of a circle that has the circumference of 400
Answer:
400/π
Step-by-step explanation:
Well, we know that the formula for circumference is πd. (d is the diameter) Then, we set up the equation 'πd = 400'. Now, simplifying for d, we get d = 200/π.
Answer:
400/π
Step-by-step explanation:
Plz help!! Given: DE is a midsegment of ABC. Show all work.
Find the value of x and y.
And What is the length of AC? !Please show all work!
Incase photo is blurry
AE-y+6
EC-x-3
DE-x+2
BC-24
Answer:
AC=14
X=10
Y=1
Hoped this helped!
Step-by-step explanation:
DE is half of BC, therefore x=10. AE and EC have to be the same length, which is 7. SO, y=1 and x is 10.
The population in millions of a city t years after 1990 is given by the equation p(t) = 2.9+0.08t in this function
Answer:
The answer would be 2.9 million is the population of the city in 1990 and 0.08 million is the increase per year in the population.
Hope it help and if it its correct please give brainliest
Stay Safe And Healthy
Thank You
1 3/10 x 18 please show work and answer
Answer:
Step-by-step explanation:
1 3/10 x 18
(1 x 10 +3)/10 = 13/10
13/10 x 18 = (13 x 18) / 10 = 234/10 = (234/2) / (10/2) = 117/5 = 23 2/5 (a fraction is a division)
The answer to the expression showing the product of 1 3/10 x 18 is 23 2/5.
Given is an expression showing the product of 1 3/10 x 18, we need to solve it,
To multiply a mixed number by a whole number, you can convert the mixed number to an improper fraction and then multiply the fractions.
Here's how you can solve the problem:
Step 1: Convert the mixed number to an improper fraction:
1 3/10 = (1 × 10 + 3) / 10 = 13/10
Step 2: Multiply the fractions:
13/10 x 18/1 = (13 x 18) / (10 x 1) = 234 / 10
Step 3: Simplify the fraction, if possible:
234/10 can be simplified by dividing both the numerator and denominator by their greatest common divisor, which is 2:
234/10 = (234 ÷ 2) / (10 ÷ 2) = 117/5
Therefore, 1 3/10 x 18 = 117/5.
Alternatively, you can express the answer as a mixed number by dividing the numerator by the denominator:
117 ÷ 5 = 23 with a remainder of 2
So, the final answer is 23 2/5.
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find measurement 1 and 4
Answer:
the info they gave us is to suppose that angle 6 is = 126°
step 1:
We know that angle 8 = angle 6 = 126°
Why? — when a circle (360°) is split by 2 lines that intersect, there will be 2 equal pairs of angles formed
step 2:
angle 2 = angle 8 = 126°
Why? — they’re alternate angles
step 3:
angle 4 = angle 2
Why? — when a circle (360°) is split by 2 lines that intersect, there will be 2 equal pairs of angles formed
step 4:
angle 1 = 180-126 (angle 4) = 54°
Why? — total angles in a straight line = 180°
Key Term:
Alternate angles:
Alternate angles are angles that occur on opposite sides of the transversal line and have the same size. Alternate angles are equal: We can often spot interior alternate angles by drawing a Z shape: There are two different types of alternate angles, alternate interior angles and alternate exterior angles.
a rectangle is made by joining two squares adjacent to each other as shown below. if one squared has an area of 144 squared centimeters what is the area of the rectangle?
Answer:
Step-by-step explanation:
2(144) = 288 cm²
Complete the table for an object that goes 3/4 mile in 6 minutes .
[tex] \frac{25}{ \sqrt[3]{5} } [/tex]write ^ as a power of 5
Answer:
[tex]5^{\frac{5}{3} }[/tex]
Step-by-step explanation:
Using the rules of exponent
[tex]\sqrt[3]{a}[/tex] = [tex]a^{\frac{1}{3} }[/tex]
[tex]\frac{a^{m} }{a^{n} }[/tex] = [tex]a^{(m-n)}[/tex]
[tex]\frac{25}{\sqrt[3]{5} }[/tex]
= [tex]\frac{5^2}{5^{\frac{1}{3} } }[/tex]
= [tex]5^{\frac{6}{3}-\frac{1}{3} }[/tex]
= [tex]5^{\frac{5}{3} }[/tex]
2/-2.5+4.1+1.2(3+6)/-0.1
Answer:
-104.7Step-by-step explanation:
2 : (-2.5) + 4.1 + 1.2 * (3+6) : (-0.1 ) =
-0.8 + 4.1 + 10.8 : (-0.1) =
-0.8 + 4.1 + (-108) =
3.3 - 108 =
-104.7
What is the volume of an oblique square pyramid with base edges 25 ft and height 24ft?
A. 5,000 ft^3
B. 7,500 ft^3
C. 10,000 ft^3
D. 15,000 ft^3
Check the picture below.
x^3-3x^2+x-2/10x^4-14x^3-10x^2+6x-10
Answer:
The quotient is 10x+16
The remainder is 28x^2+10x+22
Sara has only nickels in her hand, and David has exactly the same
number of dimes and no other coins. Together, they have a total of $1.05. How many nickels does Sara have? How many dimes does David have? Show your work
using numbers, labeled sketches, or words.
Celia's scores in the 5 quizzes Math are 18,12,15,19. What is her average score in Math?
d. 18
a. 15
c. 17
b. 16
Step-by-step explanation:
(18+12+15+19)÷5
64÷5
15
8.2 is 2% of what number
Answer:
Step-by-step explanation:
If 2% × 410 = 8.2 => Divide 8.2 by 410And see if we get as a result: 2% Note: Multiply a number by the fraction 100/100, and its value doesn't change.
Answer:
m = 410
Step-by-step explanation:
Let the number be n. Then:
8.2
--------- = 0.02
n
Cross-multiplying yields 0.02n = 8.2, from which we find n = 410
Recall that a percentage, such as 2%, is equivalent to a decimal fraction, such as
2%
-------- = 0.02
100%
Let be an angle in quadrant I such that sin +10 Find the exact values of sec 0 and tan 0.
Answer:
just look at picture's That's the answer
write the fraction as a decimal use bar notatin if necessary
-2 5/22
Answer:
1.13
Step-by-step explanation:
to turn a fraction to a decimal divide the denomitator by the numerator [tex]\frac{-25}{22}[/tex] can also be written as -25÷22 which equals 1.13 or 1.136 with a line over it
Hope this helps!
The formula for the area of a trapezoid is A= 1/2h(b1+b2), Where h is the height and b1 and b2 are the two bases. Rewrite the formula to solve for b1 in terms of A, h, and b2.
Answer:
Correct choice: B
Step-by-step explanation:
Equation Solving
The area of a trapezoid with height h and bases b1 and b2 is given by:
We must solve this formula for h.
First, multiply by 2 to eliminate denominators:
Now, divide by b1+b2:
Swapping sides:
Correct choice: B
all graphs range from -10 through 10 ;)
Answer:B
Step-by-step explanation:
Answer:
D
Step-by-step explanation:
First, we want to find out what is X.3x = -6 ---> x = -2
X is -2 so we want the graph point to start at -2 and from there go down to -10.If
x
=
4
and
y
=
7
, evaluate the following expression:
2
(
4
x
+
3
y
)
Answer:
expression.
2(4x+3y)
2(4(4)+3(7))
2(16+21)
2( 37)
74
For constant term: f(a,b,g(t)), pattern term: f(a,Y,X) when pattern matching we can use the following assignment Y=b and X=g(t) to make the two terms match.
Note: A variable in the pattern is allowed to match anything in the other structure.
What do the uppercase letters X,Y represent?
Answer:
fuctions and constants
Step-by-step explanation:
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Jamal had $25.00. He spent $9.00. Which decimal represents the fraction of the $25.00 that
Jamal spent?
A. 0.64
B. 0.36
C. 04
D. 06
Answer:
B. 0.36
Step-by-step explanation:
9/25 = x/100
9x100= 900
900 divided by 25 will be 36/100, so 0.36
An electrician must use 15 miles of electrical cable between electric poles. How many yards of cable will be used?
13,200
26,400
39,600
79,200
158,400
Answer:
B) 26,400
An electrician must use 15 miles of electrical cable between electric poles. How many yards of cable will be used?
13,200
26,400
39,600
79,200
158,400
26400 yards of cable is used.
the answer is B) 26,400
What is unit conversion?
Unit conversion is the process of changing a physical quantity from one unit of measurement to another. For example, converting kilometers to miles, Celsius to Fahrenheit, or liters to gallons. The process involves multiplying or dividing the original measurement by a conversion factor, which is a ratio of equivalent units
To convert miles to yards, we need to multiply by the conversion factor of 1 mile = 1760 yards.
15 miles * 1760 yards/mile = 26,400 yards
So, the electrician will use 26,400 yards of cable.
Hence, 26400 yards of cable is used.
the answer is B) 26,400
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