Her area of study is too narrow. There are other sources of water in the city that she is not considering. So her sample is too biased leaning toward the Uncle's pond water, and that leaves out every other source. We say that the Uncle's source of water is over-represented while the other sources are completely under-represented.
Let's put it this way: We have a hypothetical city that has 100 acres of pond water either in or surrounding the city limits. If the Uncle's pond only represents 1% of this, then she's ignoring the other 99% of the ponds.
What Lila needs to do to to fix this error is to draw up a map of each major pond and mark those ponds with numbers 001,002,...998,999. In this example, there are 999 ponds. Then she needs to either use a random number table or computer software to help randomly generate values to help select the ponds. Doing so will ensure that she spans a good portion of the city and not stay focused on just the narrow area of her Uncle's backyard.
The reason why she needs to enlarge her area of study is because the results of her Uncle's pond study may lead to the wrong conclusion of the city overall. Let's say his pond is contaminated somehow, and it's only his pond that's the unfortunate one. She would likely see the pond is contaminated and conclude that the whole city's water is ruined as well, which isn't the case. Or we could have nearly the entire city's pond water in trouble, but her Uncle's pond is one of the lucky ponds not to get contaminated. We can see that Lila would likely conclude that no action needs to be taken to clean up the city's water sources, which is also not the case.
If Lila only cared about her Uncle's pond, then that pond (and perhaps immediate close surrounding area) would be her population of study. However, her study is about citywide pond water which is why she needs to extend to other places in the city or in the outer surrounding areas.
If someone could help it would mean a lot..
Based on the graph, how much did Lydia charge for each ounce of pumpkin seeds?
A $0.50
B $1.00
C $2.00
D $12.00
Please answer the question and don’t put weird stuff
Answer:
the answer is c 2 dollars
Parents of students at a middle school
were randomly selected to participate
in a survey. Forty-two out of 60 parents
who were surveyed support a proposal to
buy new computers. There are a total of
456 parents with students at the middle
school. Which is the best estimate of the
number of those parents likely to support
the new proposal?
A. 182
B. 319
C. 365
D. 438
Answer:
(B). 319
Step-by-step explanation:
[tex]\frac{42}{60}[/tex] = [tex]\frac{x}{456}[/tex]
[tex]\frac{7}{10}[/tex] = [tex]\frac{x}{456}[/tex]
x = [tex]\frac{7*456}{10}[/tex] ≈ 319
The best estimate of the number of those parents likely to support the new proposal is 319. So the option is (B) 319.
What is constant of proportionality?Firstly, there is proportional relationship.
Two values x and y are said to be in a proportional relationship if x=ky, where x and y are variables and k is a constant.
The constant k is called constant of proportionality.
Parents of students at a middle school were randomly selected to participate in a survey.
42 out of 60 parents who were surveyed support a proposal to buy new computers.
There are a total of 456 parents with students at the middle-school.
[tex]\dfrac{42}{60} = \dfrac{x}{456} \\\\\\x = \dfrac{42}{60} \times 456\\\\x = \dfrac{7}{10} \times 456\\\\x = 319[/tex]
Therefore, the best estimate of the number of those parents likely to support the new proposal is 319.
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List all multiples of 10 up to 100.
plzzz zhelpppp plzzz
Answer: true
Step-by-step explanation:
Answer: true
Step-by-step explanation:
Find X (Someone Help)
Answer:
x=177
Step-by-step explanation:
vertically opp angles are equal so 149=x-28, to find x you do 149 +28 whiichis 177
Consider the quadrilateral shown below that has vertices A, B, C, and D.
Suppose we know the following measurements:
¯¯¯¯¯¯¯¯AB=5.8 cm
¯¯¯¯¯¯¯¯BC=5.4 cm
¯¯¯¯¯¯¯¯¯CD=3.3 cm
¯¯¯¯¯¯¯¯¯AD=6.2 cm
m∠A=27∘
What is the degree measure of ∠C?
m∠C= °
Answer:
C = 25.94°
Step-by-step explanation:
By applying cosine rule in ΔABD,
BD² = AB² + AD² - 2(AB)(BD)cosA
BD² = (5.8)² + (6.2)² - 2(5.8)(6.2)(cos27°)
BD² = 33.64 + 38.44 - 64.08
BD² = 8
BD = √8
By applying cosine rule in ΔBCD,
BD² = BC² + CD²- 2(BC)(CD)cosC
(√8)² = (5.4)²+ (3.3)² - 2(5.4)(3.3)cosC
8 = 29.16 + 10.89 - 35.64cosC
35.64cosC = 32.05
cosC = 0.89927
C = [tex]\text{cos}^{-1}(0.89927)[/tex]
C = 25.94°
By using cosine formula of triangles we got that measure of ∠C is 25.94 °
What is a quadrilateral ?Quadrilateral is a closed shape with 4 sides and 4 corners.
Here given that
AB=5.8 cm
BC=5.4 cm
CD=3.3 cm
AD=6.2 cm
and [tex]\angle A=27[/tex] °
in [tex]\triangle \mathrm{ABD}[/tex]
Applying cosine formula
[tex]$$\begin{aligned}&\mathrm{BD}^{2}=\mathrm{AB}^{2}+A D^{2}-2(\mathrm{AB})(\mathrm{BD}) \cos A \\\\&\mathrm{BD}^{2}=(5.8)^{2}+(6.2)^{2}-2(5.8)(6.2)\left(\cos 27^{\circ}\right) \\\\&\mathrm{BD}^{2}=33.64+38.44-64.08\\ \\&\mathrm{BD}^{2}=8 \\\\&\mathrm{BD}=\sqrt{8}\end{aligned}$$[/tex]
Now in [tex]\triangle B C D[/tex]
Applying cosine formula
[tex]$$\begin{aligned}&\mathrm{BD}^{2}=\mathrm{BC}^{2}+\mathrm{CD}^{2}-2(\mathrm{BC})(\mathrm{CD}) \cos \mathrm{C} \\\\&(\sqrt{8})^{2}=(5.4)^{2}+(3.3)^{2}-2(5.4)(3.3) \cos \mathrm{C} \\\\&8=29.16+10.89-35.64 \cos \mathrm{C}\\ \\&35.64 \cos \mathrm{C}=32.05\\ \\&\cos \mathrm{C}=0.89927 \\\\&\mathrm{C}=\cos ^{-1}(0.89927) \\&\end{aligned}$$[/tex]
C=25.94 °
By using cosine formula of triangles we got that measure of ∠C is 25.94 °
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The work of a student trying to solve the equation 2(2x − 3) = 6 + 2x + 4 is shown below:
Step 1: 2(2x − 3) = 6 + 2x + 4
Step 2: 4x − 3 = 10 + 2x
Step 3: 4x − 2x = 10 + 3
Step 4: 2x = 13
Step 5: x = 6.5
In which step did the student first make an error and what is the correct step? (4 points)
Group of answer choices
Step 3: 4x + 2x = 10 + 3
Step 2: 4x − 3 = 2 + 2x
Step 3: 4x − 2x = 10 - 3
Step 2: 4x − 6 = 10 + 2x
Answer:
Step 2: 4x - 6 = 10 + 2x
Step-by-step explanation:
2 needs to be distributed to all terms inside the parentheses.
Answer:
Step 2 is wrong, and the right step 2 is 4x − 6 = 10 + 2x
Step-by-step explanation:
The student didn't multiply 2(3) in step 2
A right triangle is shown with an angle that measures 60 degrees. The leg adjacent to the 60 degree angle is labeled 5. The leg opposite of the 60 degree angle is labeled x. The hypotenuse is labeled 10. Find the value of x. If your answer is not an integer, leave it in simplest radical form. The diagram is not drawn to scale.
Answer:
[tex]x = 5 \sqrt{3} [/tex]
Step-by-step explanation:
Please see the attached pictures for the full solution.
Simplify (1-x-x^2)(1-x^3)
Answer:
x^ 5 + x ^4 − x^ 3 − x^ 2 − x + 1
Step-by-step explanation:
(*￣3￣)╭
Answer:
Simplified: x^5 + x^4 - x^3 - x^2 - x +1
Step-by-step explanation:
Nixon receives an annual salary of $55,770. He receives 26 equal paychecks during the year. How much does he receive in each paycheck?
Answer:
2145
Step-by-step explanation: 55,770/26=2145
Answer:
answer = 2145 per paycheck
Step-by-step explanation:
Which triangles are similar to AED? Please help!!!
Answer:
DEF, EAD, or DEA
Step-by-step explanation:
this is because you can mix up the letters and still be a different combination with the same answer
Please help me, I don’t understand!
Answer:
y=9x+7
Step-by-step explanation:
the number in front of x is always the slope and the number after it is the Y intercept where the line first crosses the Y axis
26.) Using x as the unknown number, write the statement below as an equation.
The sum of twice a number and 7 is equal to the sum of the number and 6
Answer:
true
Step-by-step explanation:
Solve |3x – 2| = |x + 1| Question 12 options: A) x = 3∕2 or x = 1∕4 B) No solutions C) x = 3 or x = –4 D) x = 1∕4
Answer:
x = 3/2
Step-by-step explanation:
Step (1) :
We should put like term togther:
3x - x = 2 +1
2x = 3
Step (2) :
Divide bothe side by 2:
2x/2 = 3/2
x = 3/2
Which equation has the greatest positive rate of change?
O y = x - 2
O y = 4x + 4
O y = 2x - 4
O y = 0
Answer:
y=4x+4
Step-by-step explanation:
It has the biggest slope of the equations of 4, and increases the most.
A salesperson at a jewelers store earns 5% commission each week. Last week, heidi sold $530 worth of jewelry. How much did she make in commission? How much did the jewelry store make from her sales?
Answer:
the salesperson earned 5% which is; $26.5 then subtract 26.5 from the total made to find out how much the store made which is: $503.5
Step-by-step explanation:
Write an equation or inequality
1.) eight less than twice a number is more than 18.
Answer:
8 - 2n > 18
Step-by-step explanation:
8 less than 2 * a number so represent it with a variable 8 - 2*n
then more than so > 18
Please show all work(open the question to see the image)
9514 1404 393
Answer:
20
Step-by-step explanation:
The two angles shown are complementary. The corner angles in a rectangle are right angles: 90°.
(4x -12) +(x +2) = 90
5x = 100 . . . . . . collect terms, add 10
x = 20 . . . . . . . . divide by 5
Si un conductor llena su tanque con $600 y recorre 250 kilómetros, ¿Cuántos kilómetros podrá recorrer con $350 de combustible? (Explica cómo llegaste a tu respuesta)6666
Answer:
145.83 kilómetros.
Step-by-step explanation:
Si un conductor llena su tanque con $600 y recorre 250 kilómetros, para determinar cuántos kilómetros podrá recorrer con $350 de combustible se debe realizar el siguiente cálculo:
600 = 250
350 = X
350 x 250 / 600 = X
87,500 / 600 = X
145.83 = X
Así, con $350 de combustible se podrán recorrer 145.83 kilómetros.
can someone solve this? I appreciate it a lot
Answer:
No simple
Step-by-step explanation:
So... I have looked at this question I see that you use the right angle of 90 degress and the times that by 9x
^
2
With the factor of mostly what you are learning so that shows that negavtive -65 and 8, 1, 9,3 so the answer is...................... dun dun dun dun your gonna have to scroll for it hahahahah
cold
warmer but still cold
heheheh
nope
THE ANSWER IS: I DON'T KNOW How great is that?!
PLEASE HELP ME AND MY FRIEND WITH THIS PROBLEM!!
Answer:
Yo i gotta be honest, I do not know
Step-by-step explanation:
Kristl has saved 30%
of her tuition for
dance class. She
needs to have $600
save. How much has
she saved so far?
Answer:
$180
Step-by-step explanation:
please help me i have to find a table but I don't know how to
Answer:
it is one of the bottom 2 I think:)
The original price and percent paid of a 20% discount and a $14.40 sale price.
An airplane takes off 200 yards in front of a 60 foot building. At what angle of elevation must the plane
take off in order to avoid crashing into the building?
Answer:
16.69°
Step-by-step explanation:
Given that,
Height of the building, h = 60 foot
Distance from the base of the building, b = 60 foot
We need to find the angle of elevation must the plane takes off in order to avoid crashing into the building. So,
[tex]\tan\theta=\dfrac{60}{200}\\\\\theta=\tan^{-1}\dfrac{60}{200}\\\\=16.69^{\circ}[/tex]
So, the required angle is 16.69°.
please hurry up and answer
Answer:
y = 2x + 8
Hope this helps
How do u solve this?
Answer:
? = 2 Full Answer: 1/2
Step-by-step explanation:
A regular die has only 6 numbers: 1, 2, 3, 4, 5, & 6.
In those numbers, there are 3 odd numbers, and 3 even numbers. This would mean that the probability of getting an odd number would be 3/6.
But to simplify it, 3/6 ALSO equals 1/2
Answer:
1/2 is the answer
Step-by-step explanation:
A die has 6 possible outcomes: 1, 2, 3, 4, 5, 6
Out of these numbers 3 are odd numbers.
P(Event) = Number of favourable outcomes/ Total number of outcomes
P(odd) = 3/6
= 1/2
Pls help 20 points
7th grade math
Answer:
no
Step-by-step explanation:
Answer:
No
Step-by-step explanation:
The points in the table lie on a line. Find the slope of the line. Then draw its
graph.
3.
4.
0
-3
3
х
6
-2
х
-1
0
1
3
y
2
1
-7
0
y
1
-3
5
y
o
0
I need help on number 3 and 4
Answer: I need a better picture to solve the problem
Step-by-step explanation:
. The London Eye is a popular tourist attraction in London, England and is one of the largest Ferris Wheels in the world. It has a diameter of 135 meters and makes one revolution (counterclockwise) every 30 minutes. It is constructed so that the lowest part of the Eye reaches ground level, enabling passengers to simply walk on to, and off of, the ride. Find a sinsuoid which models the height h of the passenger above the ground in meters t minutes after they board the Eye at ground level.
Answer:
[tex]y=-67.5[cos(\frac{\pi}{15}t)-1][/tex]
Step-by-step explanation:
We can start solving this problem by doing a drawing of London Eye. (See attached picture).
From the picture, we can see that the tourists will start at the lowest point of the trajectory, which means we can make use of a -cos function. So the function will have the following shape:
[tex]y=-Acos(\omega t)+b[/tex]
where:
A=amplitude
[tex]\omega[/tex] = angular speed.
t= time (in minutes)
b= vertical shift.
In this case:
A= radius = 67.5 m
[tex]\omega=2\pi f[/tex]
where the frequency is the number of revolutions it takes every minute, in this case:
[tex]f=\frac{1}{30} rev/min[/tex]
so:
[tex]\omega=2\pi (\frac{1}{30})[/tex]
[tex]\omega=\frac{\pi}{15} rad/min [/tex]
and
b= radius, so
b=A
b=67.5m
so we can now build our equation:
[tex]y=-67.5cos(\frac{\pi}{15} t)+67.5[/tex]
which can be factored to:
[tex]y=-67.5[cos(\frac{\pi}{15}t)-1][/tex]
You can see a graph of what the function looks like in the end on the attached picture.
The required sinusoidal equation is [tex]y = -67.5 (cos\dfrac{\pi t}{15} -1)[/tex]
Given that,
It has a diameter of 135 meters and makes one revolution (counterclockwise) every 30 minutes.
It is constructed so that the lowest part of the Eye reaches ground level, enabling passengers to simply walk on to, and off of, the ride.
We have to find,
A sinusoidal which models the height h of the passenger above the ground in meters t minutes after they board the Eye at ground level.
According to the question,
The tourists will start at the lowest point of the trajectory, which means we can make use of a -cos function. So the function will have the following shape:
[tex]y = -Acos(wt) + b[/tex]
Where, A=amplitude , [tex]\omega[/tex] = angular speed, t= time (in minutes) , b= vertical shift.
Then,
[tex]Radius = \dfrac{diameter}{2}\\\\Radius = \dfrac{135}{2}\\\\Radius = 65.5m[/tex]
The frequency is the number of revolutions it takes every minute is determined by the formula is,
[tex]\omega = 2\pi f[/tex]
Where,
[tex]f = \dfrac{1}{30} revolution \ per \ minute[/tex]
Then,
[tex]\omega = 2\pi \times \dfrac{1}{30}\\\\\omega = \dfrac{\pi }{15}\ radian \ per\ minute[/tex]
Here, The sinusoidal equation can be written as;
[tex]y = -67.5cos\dfrac{\pi t}{15} + 67.5\\\\y = -67.5 (cos\dfrac{\pi t}{15} -1)[/tex]
Hence, The required sinusoidal equation is [tex]y = -67.5 (cos\dfrac{\pi t}{15} -1)[/tex]
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