Answer:
16.8
Step-by-step explanation:
21-4.2= 16.8
In trying to determine whether air pollution causes reduction in children's lung health a researcher proposes to see if the lung volume of 10-year-old boys who live in high ozone pollution is significantly less than the lung volume of all 10-year-old boys. The mean volume for all 10-year-old boys is 2.05 liters. A random sample of 26 10-year-old boys who live in a community with high levels of ozone pollution is found to have a mean volume of 1.98 liters, with a sample standard deviation of 0.3 liters. Test the researcher's claim that the mean lung volume of 10 -year-old boys who live in a community with high levels of ozone pollution is less than 2.05 at the 5% significance level.
Answer:
The test statistic will be "-2.33". A further explanation is provided below.
Step-by-step explanation:
According to the question,
[tex]H_0: \mu = 2.05[/tex]
[tex]H_0: \mu < 2.05[/tex]
Given:
[tex]\bar x = 1.98[/tex]
[tex]s = 0.3[/tex]
[tex]n = 100[/tex]
The test statistics will be:
⇒ [tex]t_0 = \frac{\bar x - \mu_0}{\frac{s}{\sqrt{n} } }[/tex]
[tex]=\frac{1.98-2.05}{\frac{0.3}{\sqrt{100} } }[/tex]
[tex]=-2.33[/tex]
and the P-value will be:
= [tex]0.011< \alpha[/tex]
(solving rate problems). Michelle can
complete a
landscaping job in 6
days and Danielle
can complete the
same job in 4 days.
Working together, in
how many days
could they complete
the job
They could complete the job together in 2.4 days
The known parameters are;
The number of days it would take Michelle to complete the landscaping job = 6 days
The number of days it would take Danielle to complete the landscaping job = 4 days
The unknown parameter;
The number of days can the job be completed if they work together
The process of finding the solution;
The rate at which Michelle works = 1/6 of the landscaping work per day
The rate at which Danielle works = 1/4 of the landscaping work per day
Method;
Find their combined work rate, from which the time would take them to complete the job together can be found
Let, C, represent their combined work rate
Therefore, we have;
C = (1/6 + 1/4) = 5/12 of the landscaping (work) job/(per) day
The number of days they could complete the, 1, job = 1 job(work)/(5/12 (work)job/day) = 12/5 days = 2.4 days
∴ The number of days they could complete the job together = 2.4 days.
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What are the solutions to the system of equations?
{y=2x²−6x+3
{y=x−2
Answer:
x = 1, y = −1
x = 5/2, y = 1/2
Step-by-step explanation:
From the question given above, the following data were obtained:
y = 2x² − 6x + 3 ........ (1)
y = x − 2 ...... (2)
We can obtain the solutions to the equation as follow:
y = 2x² − 6x + 3 ........ (1)
y = x − 2 ...... (2)
Substitute the value of y in equation 2 into equation 1
y = 2x² − 6x + 3
y = x − 2
2x² − 6x + 3 = x − 2
Rearrange
2x² − 6x − x + 3 + 2 = 0
2x² − 7x + 5 = 0
Solve by factorization
Obtain the product of 2x² and 5. The result is 10x².
Find two factors of 10x² such that their sum will result to −7x.
The factors are −2x and −5x.
Replace −7x in the equation above with −2x and −5x as shown below:
2x² − 2x − 5x + 5 = 0
2x(x − 1) − 5(x − 1) = 0
(x − 1)(2x − 5) = 0
x − 1 = 0 or 2x − 5 = 0
x = 1 or 2x = 5
x = 1 or x = 5/2
Substitute the value of x into equation 2 to obtain y
y = x − 2
x = 1
y = 1 − 2
y = −1
x = 5/2
y = x − 2
y = 5/2 − 2
y = (5 − 4)/2
y = 1/2
SUMMARY:
x = 1, y = −1
x = 5/2, y = 1/2
Rita offers to pay for 8 of her friends to play laser tag, but 3
of them don't want to play.
If laser tag costs $5 per person, how much will Rita spend on her friends?
Choose the correct expression and solution to this problem,
Last Option
Rita will spend $25
5(8-3)
Answered by Gauthmath must click thanks and mark brainliest
Answer: The correct answer is D.
Step-by-step explanation:
Since 3 of Rita's 8 friends don't want to play laser tag, Rita only has to pay for 5 of her friends to go.
So, the expression would be:
5 (8 - 3)
= 5 (5)
= $25
Hope this helps! :)
whats the area in square inches
Answer:
Area of triangle =1/2b×h
1/2×10×8.7
=44 square inches
Answer:
44
Step-by-step explanation:
The area of a triangle is given by
A = 1/2 bh
where b is the base and h is the height
A = 1/2 (10) (8.7)
A= 43.5
Rounding to the nearest whole number
A = 44
if sinA=4/5 and cosB=12/13 find the value of:
Sin2A
Answer:
24/25
I hope this will help you.
1. Calculate the slope of a line going trough A (-4,3) and B (0,6)
2. Calculate the slope of a line with a run of 3 and a rise of 9
3. Calculate the equation if two points are (1,6) and (5,0)
I need help to find the missing side of this right triangle
Answer:
[tex]\sqrt{136}[/tex]
Step-by-step explanation:
Formula for Pythagorean theorem: [tex]a^{2} +b^{2} = c^{2}[/tex]
Plug in:
[tex]6^{2}+10^2=x^2[/tex]
Solve:
36 + 100 = [tex]x^{2}[/tex]
136 = [tex]x^{2}[/tex]
[tex]\sqrt{136}[/tex] = x
The answer is [tex]\sqrt{136}[/tex].
Hope this helped.
tìm kiếm x y z
x-1/y =1
y-1/z =1
z-1/x =1
y - 1/z = 1 ==> y = 1 + 1/z
z - 1/x = 1 ==> z = 1 + 1/x
==> y = 1 + 1/(1 + 1/x) = 1 + x/(x + 1) = (2x + 1)/(x + 1)
x - 1/y = x - (x + 1)/(2x + 1) = (2x ² - 1)/(2x + 1) = 1
==> 2x ² - 1 = 2x + 1
==> 2x ² - 2x - 2 = 0
==> x ² - x - 1 = 0
==> x = (1 ± √5)/2
If you start solving for z, then for x, then for y, you would get the same equation as above (with y in place of x), and the same thing happens if you solve for x, then y, then z. So it turns out that x = y = z.
Pleeeeeeeeaaaaaaaaaaaasse help 71 points!!!!!!!!!
Answer:
54
Step-by-step explanation:
The perimeter is the sum of the outside
P = 8+4+5+10+( 4+10) +(8+5)
P = 54
What is the slope of the function? Then changed the line so it had a slope of 2, but still went through the same point. Which equation should Alejandra write to represent the new line?
Complete question is;
Alejandra correctly wrote the equation y – 3 = (1/5) (x – 10) to represent a line that her teacher sketched. The teacher then changed the line so it had a slope of 2, but still went through the same point. Which equation should Alejandra write to represent the new line?
Answer:
y – 3 = 2(x – 10)
Step-by-step explanation:
Since the original line is;
y – 3 = (1/5) (x – 10)
This means the slope is 1/5 and the x and y coordinates are (10, 3) respectively.
Now, if she changes the slope to 2 and it still passed through the same point, then it means it's x and y points are still (10, 3). Thus, the equation will now be;
y – 3 = 2(x – 10)
solve for θ.
sin(74) = cos(θ)
1. 6°
2. 74°
3. 36°
4. 16°
Sin74 = Cos16
cause 16 + 74 = 90
Whenever the sum of two angles is equal with 90, the Sin of one is equal with the Cos of the other like :
Sin(30) = Cos(60)
and also
Tan(30) = Cot(60)
Answer:
16
Step-by-step explanation:
sin(74) = cos(x)
sin(x)=cos(90-x)
sin (74) = cos(90-74)
sin 74 = cos( 16)
In the diagram provided, line l is parallel to line m. Select which of the following statements could be used to prove that the interior angles of a triangle have a sum of 180°. You may choose more than one correct answer.
m 4 + m 5 + m 6 = 180.
1 and 4 are alternate interior angles.
m 5 = m 3 + m 2
. m 5 + m 1 = 180.
Answer:
all except the first
Step-by-step explanation:
do u really want an explanation
How to find interquartilte range
============================================================
Explanation:
Each x represents a data point location.
So, for example, having an x over 60 means 60 is part of the set.
The set of values we're working with is
{59,60,61,63,63,64,66,68,70,71,71,73}
The repeated values are due to the fact we have a stack of two 'x' markers, and they occur at 63 and 71.
To find the IQR (interquartile range), we'll first need to find the median of this set. That's the middle most value.
Count out the number of values to find that there are n = 12 values.
The list splits into two halves that are n/2 = 12/2 = 6 items each
Between slots 6 and 7 is where the median is located.
The value in slot 6 is 64 and the value in slot 7 is 66. Average those two items to get (64+66)/2 = 65
The median is 65
---------------------------------
Next, we'll form two groups L and U such that
L = set of items lower than the median
U = set of items larger than the median
Because n is even, we simply just break the original set into two equal groups (6 items each)
L = {59,60,61,63,63,64}
U = {66,68,70,71,71,73}
The values of Q1 and Q3 represent the medians of L and U in that order.
The median of set L is (61+63)/2 = 62, so Q1 = 62
The median of set U is (70+71)/2 = 70.5, which is Q3
-----------------------------------
To summarize everything so far, we have found
Q1 = 62Q3 = 70.5Subtract those items to get the IQR
IQR = Q3 - Q1
IQR = 70.5 - 62
IQR = 8.5 which points us to choice C as the final answer.
If mn, solve for x.
(3x + 9) (x + 21)
2
3x. + 63x + 9x + 189
Step-by-step explanation:
Use distributive law, in other words multiply the first bracket terms by the second bracket terms
square root of 800 to the nearest thousandth
Answer:
28.284
Step-by-step explanation:
PLEASE HELP!!
BRAINLYEST TOO 1st
9514 1404 393
Answer:
A, C
Step-by-step explanation:
Any table with no repeated x-values is a relation that is a function.
1. When decimal currency came to Australia in 1966 (that's exactly
50 years ago!), there were 6 coins -- 1 cent, 2 cent, 5 cent,
10 cent, 20 cent and 50 cent coins. What is the SMALLEST
number of these coins you would need to make 89 cents?
Doing this, we get that the smallest number of coins is: 6
89 cents:
89 is more than 50 cents, but less than 50*2 = 100, so 1 50 cent coin is needed, which leaves 89 - 50 = 39 cents remaining.39 is more than 20 cents, but less than 20*2 = 40, so 1 20 cent coin is needed, which leaves 39 - 20 = 19 cents remaining.19 is more than 10 cents, but less than 10*2 = 20, so 1 10 cent coin is needed, which leaves 19 - 10 = 9 cents remaining.9 is more than 5 cents, but less than 5*2 = 10, so 1 5 cent coin is needed, which leaves 9 - 5 = 4 cents remaining.The remaining 4 cents are achieved with 2 2 cent coins.Thus, the smallest amount of coins needed is 1 + 1 + 1 + 1 + 2 = 6.
A similar question can be found at https://brainly.com/question/21776594
Which point should Julio use to determine the amount of pizza sauce he needs to bring?
A
B
C
D
On a coordinate plane, a graph titled Pizza Recipe has Pizzas on the x-axis and Cups of Pizza Sauce on the y-axis. Point A is (3, 2), point B is (4, 2.6), point C is (4.5, 3), point D is (6, 4).
Answer:
The question is incomplete, but after a small search I've found that the complete question is something like:
To celebrate something, a teacher will make pizzas for the class.
There are 30 students in his class and each pizza serves 8
Julio will bring the pizza sauce. Which point should Julio use to determine the amount of pizza sauce he needs to bring?
In a graph, the vertical axis is represented with the variable y, which is defined as the dependent variable, while the horizontal axis represents the variable x, which is the independent variable.
The notation for a point in that graph is (x, y)
Here, we know that the x-axis represents the number of pizzas, and the y-axis represents the number of cups of pizza sauce needed for the x pizzas.
So, for example, the point (3, 2) means that:
for x = 3 pizzas, you need y = 2 cups of pizza sauce.
So, now let's find the number of pizzas that will feed the whole class.
There are 30 students, Each pizza serves for 8.
Then the number of pizzas needed is:
30/8 = 3.75 pizzas.
But we can round it to 4 pizzas because making a 0.75 of a pizza does not make a lot of sense.
Then we could use point B, which is (4, 2.6)
This means that, for 4 pizzas, they need 2.6 cups of pizza sauce.
So Julio should bring 2.6 cups of pizza sauce.
Which point should Julio use to determine the amount of pizza sauce he needs to bring?
(B 4,26)
what is the point-slope equation of a line with slope-4 that contains the point (-2 7)\
Answer:
y - 7 = -4 (x + 2)
Step-by-step explanation:
y - 7 = -4 (x + 2)
in a survey of 100 people, 60 like farming and 65 like civil service. find the number of people who likes farming as well as civil service. also find out how many people like only civil war
Let
A=set of people like farmingB=set of people like civil service A[tex]\cup[/tex] B =Total peopleA[tex]\cap[/tex]B=People like bothWe know
[tex]\boxed{\sf n(A\cup B)=n(A)+n(B)-n(A\cap B)}[/tex]
[tex]\\ \sf\longmapsto n(A\cap B)=n(A)+n(B)-n(A\cup B)[/tex]
[tex]\\ \sf\longmapsto n(A\cap B)=60+65-100[/tex]
[tex]\\ \sf\longmapsto n(A\cap B)=125-100[/tex]
[tex]\\ \sf\longmapsto n(A\cap B)=25[/tex]
1 pump fill resovoir in 60 hrs other 80 hrs other 90 hrs when they are together how long to fill resovoir? Rsm
Answer:
24.83 hours
Step-by-step explanation:
Given that :
Let time taken by pumps be :
Pump A = 60 hours
Pump B = 80 hours
Pump C = 90 hours
Recall :
Rate = 1 / time taken
The rates of the pumps are :
Pump A rate = 1 / 60
Pump B rate = 1/80
Pump C rate = 1/90
Combined rate : 1/60 + 1/80 + 1/90
Combined rate = (12 + 9 + 8) / 720 = 29/720
Combined rate = 29/720
The time taken together will be :
1 / combined rate = 1/(29/720) = 720 / 29 = 24.827 hours
Find the equation of a line perpendicular to 8x - 2y = 4 and passes through the point (4, 3).
y = -2x-3
Lines that are perpendicular have slopes that are negative reciprocals of each other. Meaning, if a line has slope , then a line perpendicular to this has slope . That means the slope of our perpendicular line is
The equation of the line that is perpendicular to 8x - 2y = 4 and passes through the point (4, 3) is y = (-1/4)x + 4.
To find the equation of a line that is perpendicular to the line 8x - 2y = 4 and passes through the point (4, 3), we can use the fact that the slopes of perpendicular lines are negative reciprocals of each other.
First, let's rewrite the given equation in slope-intercept form (y = mx + b), where m represents the slope:
8x - 2y = 4
-2y = -8x + 4
Divide both sides by -2:
y = 4x - 2
The slope of the given line is 4.
The slope of a line perpendicular to this line would be the negative reciprocal of 4, which is -1/4.
Now, we have the slope (-1/4) and a point (4, 3). We can use the point-slope form of a linear equation:
y - y₁ = m(x - x₁)
Substituting the values, we have:
y - 3 = (-1/4)(x - 4)
Expanding and simplifying, we get:
y - 3 = (-1/4)x + 1
Adding 3 to both sides, we have:
y = (-1/4)x + 4
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Mike, the barista at Moose Jaw Coffee, has to mix together two kinds of coffee beans - Mocha Madness, which costs $12 a pound, and Sumatra Sweetness, which costs $20 a pound - to produce forty pounds of a coffee that costs $14 a pound. The beans in the mixture sell for the same price as they would separately. How many pounds of Mocha Madness coffee will Mike put into the mixture
Answer:
mocha madness = 30 pounds
Step-by-step explanation:
Let
x = Mocha Madness
y = Sumatra Sweetness
two equations can be derived from the question
x + y = 40 equation 1
12x + 20y = 14 x 40 equation 2
Multiply equation 1 by 12
12x + 12y = 480 eqn 3
subtract eqn 2 from 3
8y = 80
y = 10
substitute for y in equation 1
x + 10 = 40
x = 40 - 10
x = 30
8y = 180
y = 10 pounds
x = 30 pounds
Find y when = 22, if y varies directly as x,
and y = 39 when x = 7.
Answer:
let,
x=ky
y=39 when x=7 so,
7=39k
or, k=7/39
now, when x=22
22=7y/39
or, y=39×22/7
or, y=858/7
or, y=122.57 (rounded to the nearest hundredth)
marked price of an item is 4000, what will be it's selling price having 20% discount and 10% vat.
Answer:
I HOPE IT WILL HELP
EXPLANATION IS IN THE PHOTO .
Find the missing term and the missing coefficient.
(6a −_)5a =_a2 − 35a
Answer:
[tex](6a-7)5a=30a^2-35a[/tex]
Step-by-step explanation:
Message if you want a detailed explanation.
Evaluate the powers of 3 to find each value.?
Answer:
The value of 3^-2 is 1/9
Step-by-step explanation:
This is because negative exponent such as [tex]2^{-1}[/tex] transfer to 1/2. Therefore, you might notice a pattern of negative exponent -> fraction. 3^-2 -> 1/(3^2)-> 1/9
PLEASE MARK BRAINIEST IF THIS HELPED!!!
Answer:
1 /91327Step-by-step explanation:
Concept:
Here, we need to know the idea of exponents.
The exponent of a number says how many times to use the number in a multiplication.
When the exponent is positive, just multiply the base number by the number of times the exponent states.For example: 5² = 5 × 5 = 25When the exponent is negative, turn to the reciprocal of the base number, then multiply the base number by the number of times the exponent states as the denominator.For example: 6⁻² = 1 / 6² = 1 / (6 × 6) = 1/36Any number to the 0th power, it is equal to 1.
Solve:
Question 1. What is the value of 3⁻²?
The exponent ⁻² on 3² is negative3⁻² = 1 / 3² = 1 / (3 × 3) = 1/9Question 2. What is the value of 3⁰?
The exponent of 3⁰ is 03⁰ = 1Question 3. What is the value of 3¹?
The exponent of 3¹ is positive3¹ = 3Question 4. What is the value of 3³?
The exponent of 3³ is positive3³ = 3 × 3 × 3 = 27Hope this helps!! :)
Please let me know if you have any questions
Find the value of x in Circle O.
Answer:
x=8
Step-by-step explanation:
x^2+15^2=17^2, x=sqrt(64)=8
A rectangular field is to be fenced off, and then divided in two by a fence running parallel to one of the sides. If 996 meters of fencing can be used, find the dimensions of the field that will maximize the total area, and then find the maximum area. List the smaller dimension first.
Solution :
Maximize, S = xy
subject to 2x + 2y = 996
So,
2x + 2y = 996
2(x + y) = 996
x + y = 498
y = 498 - x
Therefore,
S = x (498 - x)
S = 498x - [tex]x^2[/tex]
S = [tex]-x^2 + 498x[/tex]
[tex]$S = -(x^2-498x + 249^2) + 300^2$[/tex]
[tex]$S= -(x-249)^2 + 249^2$[/tex]
S = x (498 - x)
S = 498x - [tex]x^2[/tex]
[tex]$\frac{dS}{dx}= 498 - 2x$[/tex]
[tex]$\frac{dS}{dx}= 0$[/tex]
498 - 2x = 0
2x = 498
x = 249
∴ y = 498 - x
y = 498 - 249
= 249
Answer:
A = 249 x 249 = 62001 square meter.
Side is L = 249 m
Step-by-step explanation:
Total length of the fence is 996 m.
Let the length is L and the width is W.
Perimeter = 2 (L + W)
996 = 2 (L + W)
498 = L + W
L = 498 - W ...... (1)
Let the area is
A = L W
A = (498 - W) W
A = 498 W - W^2
Differentiate with respect to W.
dA/dW = 498 - 2 W
Put it equal to zero.
498 - 2 W = 0
W = 249 m
Now, L = 498 - 249 = 249 m
Differentiate with respect to W again
[tex]\frac{d^2A}{dW^2} = - 2[/tex]
As it is negative so the area is maximum.
The maximum area is
A = 249 x 249 = 62001 square meter.
Side is L = 249 m
