Answer:
(i) (4, 0)
(ii) -2
Step-by-step explanation:
y = 4 + 3x - x^2
(i)
At point A, y = 0
4 + 3x - x^2 = 0
x^2 - 3x - 4 = 0
(x - 4)(x + 1) = 0
x - 4 = 0 or x + 1 = 0
x = 4 or x = -1
The x-coordinate of point A is positive, so it is 4.
The coordinates of point A are (4, 0).
(ii)
y = mx + 8
We know point (4, 0) is on the line, so we substitute 4 for x and 0 for y and solve for m in the slope equation.
0 = m(4) + 8
4m = -8
m = -2
Two opposing opinions were shown to a random sample of 1,500 buyers of a particular political news app in the United States. The opinions, shown in a random order to each buyer, were as follows:
Opinion A: Improving the healthcare system is more important than improving the education system.
Opinion B: Improving the education system is more important than improving the healthcare system.
Buyers were to choose the opinion that most closely reflected their own. If they felt neutral on the topics, they were to choose a third option of "Neutral."
The outcomes were as follows:
39% chose Opinion A, 54% chose Opinion B, and 7% chose "Neutral."
Part A: Create and interpret a 98% confidence interval for the proportion of all US buyers of this particular app who would have chosen Opinion B. (5 points)
Part B: The number of buyers that chose Opinion B and the number of buyers that did not choose Opinion B are both greater than 10. Why must this inference condition be met? (5 points)
Answer:
A) 98% Confidence interval for the proportion of all US buyers of this particular app who would have chosen Opinion B
= (0.51, 0.57)
This means that the true proportion of all thay would chose opinion B can take on values between the range of (0.51, 0.57)
B) For the confidence interval obtained to be valid, the conditions stated must be satisfied and for the sampling distribution to be approximately normal, the number of buyers that chose Opinion B and the number of buyers that did not choose Opinion B must both be greater than 10.
Step-by-step explanation:
Confidence Interval for the population proportion is basically an interval of range of values where the true population proportion can be found with a certain level of confidence.
Mathematically,
Confidence Interval = (Sample proportion) ± (Margin of error)
Sample proportion of all US buyers of this particular app who would have chosen Opinion B = 0.54
Margin of Error is the width of the confidence interval about the mean.
It is given mathematically as,
Margin of Error = (Critical value) × (standard Error)
Critical value at 98% confidence interval for sample size of 1500 is obtained from the z-tables.
Critical value = 2.33
Standard error = σₓ = √[p(1-p)/n]
p = sample proportion = 0.54
n = sample size = 1500
σₓ = √(0.54×0.46/1500) = 0.0128685664 = 0.01287
98% Confidence Interval = (Sample proportion) ± [(Critical value) × (standard Error)]
CI = 0.54 ± (2.33 × 0.01287)
CI = 0.54 ± 0.02998)
98% CI = (0.51, 0.57)
98% Confidence interval = (0.51, 0.57)
B) The number of buyers that chose Opinion B and the number of buyers that did not choose Opinion B are both greater than 10. Why must this inference condition be met?
For this confidence interval to be obtained using sample data, a couple of conditions are necessary to be satisfied. They include;
- The sample data must have been obtained using a random sampling technique.
- The sampling distribution must be normal or approximately normal.
- The variables of the sample data must be independent of each other.
On the second point, the condition for a binomial distribution to approximate a normal distribution is that
np ≥ 10
and n(1-p) ≥ 10
The quantity np is the actual sample mean which is the actual number of buyers that chose Opinion B while n(1-p) is the number of buyers that did not chose Opinion B.
For the confidence interval obtained to be valid, the conditions stated must be satisfied and for the sampling distribution to be approximately normal, the number of buyers that chose Opinion B and the number of buyers that did not choose Opinion B must both be greater than 10.
Hope this Helps!!!
A bag contains 20 brown, 16 orange, 4 navy, and 13 purple marbles. A marble is drawn at random. What is the theoretical probability of drawing a brown marble?
20/53 chance or 0.38 probability.
Determine the measure of the named angle below.
mZK
K
40°
Step-by-step explanation:
Bro this problem cannot be solved. No solutions. I need at least one more angle or the type of triangle it is. Like iscoceles or scalene, or equilateral. Pls give me that info and then I can solve it for u
Given segment CE and point D that lies on CE, find CD if CE= 11, CD= -16-3x, and ED= -13-2x
Answer:Assuming all three, we shall find that each of the relations in 3:14 leads to a ... Then by 3:15 the relations AD//BC and AB||DE imply AD//CE, which excludes ... From 2:72, 3:11, 3:14, and 3:16 we deduce 3:19 If A, B, C are three distinct ... a point D lies between X and Y in AB/C if it belongs to XY/C, that is, if XY||CD
Step-by-step explanation:
He randomly selects a sample of 200 Darwin households. Forty households prefer the new package to all other package designs. The point estimate for this population proportion is
Answer: The point estimate for this population proportion is 0.2
Step-by-step explanation:
The point estimate for this population proportion is also referred to as the sample proportion. This is also known as the probability of success, p. The formula for determining p is expressed as
p = x/n
Where
n represents the number of samples
x represents the number of success
From the information given,
n = 200
x = 40
p = 40/200 = 0.2
Neil goes to the pet shop and selects a treat for his dog. He chooses one, then chooses another. What is the probability Neil selects a bone and then a ball? There are 3 collars, 4 bones, and 5 balls.
Answer:
15.15% probability that Neil selects a bone and then a ball
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
Initially, there are 3+4+5 = 12 treats. 4 of those are bones. So the probability of selecting a bone is 4/12 = 1/3.
Now suppose a bone has been selected. Now there are 11 treats, 5 of which are balls. So the probability of selecting a ball in this situation is 5/11.
What is the probability Neil selects a bone and then a ball?
[tex]p = \frac{1}{3}*\frac{5}{11} = \frac{5}{33} = 0.1515[/tex]
15.15% probability that Neil selects a bone and then a ball
What type of correlation is shown by the graph?
Answer: Positive correlation
Step-by-step explanation:
As you go up and along the graph the values go up.
Both have to be increasing basically.
The question on the bottom
Answer:
9th grade student=33.3%, unit 7=45%
Step-by-step explanation:
Which formula(s) can be used to find the nth partial sum of a geometric sequence or the sum of the first n terms of a geometric series?
Step-by-step explanation:
An=A1. R raised to the power n-1
Bobby is making a cake. The recipe calls for 1( 3)/(4) cups of flour for every( 1)/(8) cups of sugar. How many cups of flour is needed for 1 cup of sugar?
If you want I will give BRAINLIEST >_
Answer:
5 cups
Step-by-step explanation:
To get 1 cup of sugar, u must add 1/8 by 8. now you have one cup of sugar. But to find out how much flour u need, u also need to multiply 1 3/4 by 8, which gives u 5 cups
Answer:
14 cups of flour are needed for 1 cup of sugar.
Step-by-step explanation:
Use a ratio.
cups of flour : cups of sugar
1 3/4 : 1/8
? : 1
We know that you must multiply by 8 to get from 1/8 to 1. Now we have to do the same to the other side. So, multiply 1 3/4 by 8.
1 3/4 * 8 = 14
Therefore, 14 cups of flour are needed for 1 cup of sugar.
Tell me if this was helpful:)
Please I need help with this one
Answer:
$0.60
Step-by-step explanation:
Given that P(A)=0.5 and P(A and B)=0.4, if A and B are independent events, what is the probability of event B?
0.2
0.1
0.8
0.9
Answer:
0.8
Step-by-step explanation:
Find two numbers, if their sum is 49 and their difference is 1/2 .
Answer:
[tex]x=24\frac{3}{4}\\ y=24\frac{1}{4}[/tex]
Step-by-step explanation:
Let the two numbers be x and y
So we have:
[tex]x +y = 49\\x-y=\frac{1}{2}[/tex]
using the elimination method, add the two equations together:
[tex]2x=49\frac{1}{2} \\2x=\frac{99}{2}[/tex]
solve for x:
[tex]x=\frac{99}{4}\\x=24\frac{3}{4}[/tex]
substitute our value for x back into the first equation we made:
[tex]x+y=49\\(\frac{99}{4}) + y=49\\y=49-\frac{99}{4}\\y=\frac{97}{4} \\ y=24\frac{1}{4}[/tex]
therefore,
[tex]x=24\frac{3}{4}\\ y=24\frac{1}{4}[/tex]
A dolphin jumped up out of the water and back into the water in a parabolic path. (H) height (t) seconds . H=-8(t-0.5)^2+2 . How long will the dolphin be in the air?
Answer:
4 seconds
Step-by-step explanation:
using the vertex formula of a quadratic,
[tex]a(x-h)^{2} + k[/tex], where (h,k) is the vertex
[tex]h = -8(t-0.5)^{2}+2[/tex] h is height and t is time in seconds
the vertex (maximum height) of the dolphin is (h,k) or (0.5, 2)
Height of 1/2
time of 2 seconds
it will take 2 additional seconds to reach the water again.
this can also be solved using quadratic equation, but since it was already set up in vertex form, i'd use that.
Could some one plz help me with this question
P.S ignore the answer choices their wrong
25 Points
Answer:
A
Step-by-step explanation:
The formula for this type of interest is [tex]A=P(1+\frac{r}{n})^{nt}[/tex], where A is the total amount, P is the initial investment, x is the interest rate, n is the amount of times that the investment is compounded a year, and t is the amount of years. Plugging in the numbers given, you get:
[tex]A=1800(1+\frac{0.025}{2})^{2\cdot 12}=[/tex]
[tex]1800(1.0125)^{24}\approx 2425.23[/tex]
Now, she invests this into a new account, and you can set up the following equation:
[tex]A=2425.23(1+\frac{0.04}{12})^{12\cdot 7}=[/tex]
[tex]2425.23(1.0033333)^{84}\approx 3207.40[/tex], or option A.
Hope this helps!
Two boats started to move towards each other from two boat stations, located 30 miles apart. One boat moved at a speed of 3 miles per hour, the other moved twice as fast. How soon will the boats meet?
Answer:
The boats will meet in 3.33 hours.
Step-by-step explanation:
The position of each boat can be modeled by a first order equation.
I am going to say that the first boat is at the position 0, and moving in the positive direction with a speed of 3 miles per hour. So
[tex]A(t) = 0 + 3t[/tex]
They are moving in oppositie directions, and initially are 30 miles apart. This means that the second boat starts at the position 30, and moves in the negative direction at the rate of 6 miles an hour. So
[tex]B(t) = 30 - 6t[/tex]
How soon will the boats meet?
This is t when:
[tex]A(t) = B(t)[/tex]
[tex]3t = 30 - 6t[/tex]
[tex]9t = 30[/tex]
[tex]t = \frac{30}{9}[/tex]
[tex]t = 3.33[/tex]
The boats will meet in 3.33 hours.
help plssssssssssssssssss
Answer:
80
Step-by-step explanation:
BECAUSE ON THE BOX PLOT ON HOW IT IS LOOK AT THAT LAST LINE AND LOOK HOW FAR IT GOES THATS HOW MUCH IT WOULD BE
BRAINLEST PLEASEHelp me it’s urgent
Answer:
∠GHJ and ∠IHJ
Answer:
[-10, 10]
This is an absolute value problem and numbers within the brackets are always seen as positive. [-10] = 10 and [10] = 10
Step-by-step explanation:
There are 2 violet balls and 4 pink balls in a bag.if two balls are drawn one after the other , then what is the probability of getting violet first and pink next, if the first ball drawn is replaced?
Answer:
c
Step-by-step explanation:
The probability of getting violet first and pink next is [tex]\dfrac{2}{9}[/tex].
Given:
The number of violet balls is 2.
The number of pink balls is 4.
To find:
The probability of getting violet first and pink next, if the first ball drawn is replaced.
Explanation:
We know that,
[tex]\text{Probability}=\dfrac{\text{Favorable outcomes}}{\text{Total outcomes}}[/tex]
Total number of balls is:
[tex]2+4=6[/tex]
The probability of getting violet a ball is [tex]\dfrac{2}{6}[/tex].
The first ball drawn is replaced, then the total number of balls remains the same. Then the probability of getting a pink ball is [tex]\dfrac{4}{6}[/tex].
The probability of getting violet first and pink next, if the first ball drawn is replaced is:
[tex]P=\dfrac{2}{6}\times \dfrac{4}{6}[/tex]
[tex]P=\dfrac{1}{3}\times \dfrac{2}{3}[/tex]
[tex]P=\dfrac{2}{9}[/tex]
Therefore, the probability of getting violet first and pink next is [tex]\dfrac{2}{9}[/tex].
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Myra is a scientist and needs 45 gallons of a 16% acid solution. The lab is currently stocked only with a 20% acid solution and a 10% acid solution. Myra will need to mix how many gallons of the 20% solution and how many gallons of the 10% solution to have what she needs.
Answer:
The volume of the solution with 20% acid is 27 gallons and the one with 10% acid is 18 gallons
Step-by-step explanation:
Myra needs to mix "x" gallons of the solution with 20% and "y" gallons of the solution with 10%. The volume of the final solution must be 45 gallons, therefore:
x + y = 45
The concentration of acid of the final solution is:
0.2*x + 0.1*y = 45*0.16
0.2*x + 0.1*y = 7.2
Therefore we have a system of equation:
x + y = 45
0.2*x + 0.1*y = 7.2
We need to multiply the first equation by -0.1:
-0.1*x -0.1*y = -4.5
0.2*x + 0.1*y = 7.2
We now sum both equation:
0.1*x = 2.7
x = 2.7/0.1 = 27 gallons
y = 45 - 27 = 18 gallons
Martin charges $10 for every 5 bags of leaves he rakes. Last weekend, he raked 27 bags of leaves. How much money did he earn?
Answer:
$54 : 27 bags
Step-by-step explanation:
its to much to explain
i got my math wrong
Pretty please for a homie
can you please help me out
Answer:
fwefwfwfewfwefwefwfew
Step-by-step fweexplanation:
erwrwerw
The measure of a straight angle (2x+50) (6x+2)
Answer:
see below
Step-by-step explanation:
If the two angles form a straight angle, their sum is 180
2x+50 + 6x+2 = 180
Combine like terms
8x +52 = 180
Subtract 52 from each side
8x+52-52 = 180-52
8x =128
divide each side by 8
8x/8 = 128/8
x =16
2x+50 = 2(16)+50 = 32+50 = 82
6x+2 = 6(16)+2 =96+2 = 98
Rewrite the equation by completing the square.
4x2 + 28x + 49 = 0
(x+) =
Answer: x = - 3.5
Step-by-step explanation:
Rewrite the equation by completing the square.
4x2 + 28x + 49 = 0
Completing the square method :
Divide through by the Coefficient of x^2
x^2 + 7x + (49/4) = 0
a = 1, b = 7, c = 49/4
Move c to the right side of the equation
x^2 + 7x = - 49/4
Complete the square on the left hand side by squaring its half of the x term
(7/2)^2 = (49/4)
Add the output to both sides of the equation
x^2 + 7x + (49/4) = - (49/4) + (49/4)
(x + 7/2)^2 = 0
Square root of both sides
x + 7/2 = 0
x = - 7/2
x = - 3.5
Answer:
x = - 3.5
Step-by-step explanation:
Which points are Coplanar and noncollinear. ?
Answer:
Non-collinear points: These points, like points X, Y, and Z in the above figure, don't all lie on the same line. Coplanar points: A group of points that lie in the same plane are coplanar. Any two or three points are always coplanar. Four or more points might or might not be coplanar.
Step-by-step explanation:
What is the rate of change
Answer:
Slope = 0
Step-by-step explanation:
Let's use the equation [tex]\frac{y2 - y1}{x2 - x1}[/tex] for this problem.
We have two points: (2,0) and (-2, 0)
Let's plug them both into the equation shown above.
[tex]\frac{0 - 0}{-2 - 2}[/tex]
Solve.
0 - 0 = 0
-2 - 2 = -4
[tex]\frac{0}{-4}[/tex] = [tex]-\frac{0}{4}[/tex] = 0
A zero in the numerator means this equation has a slope of 0.
Any line with a slope of 0 is a horizontal line.
Slope (rate of change) = 0
Simplify the radicals in the given expression:
8^3√a^4b^3c^2-14ab^3√ac^2
8ab√ac^2-14ab^3ac^2
8a^2ba^3√b-14abc^3a
8ab^3ac^2-14ab^3√ac^2
8a^2bc√b-14abc√a
i've gotten the answer it is "8ab^3ac^2-14ab^3√ac^2"
Answer: it’s option c
Step-by-step explanation:
Simplified form of radical 8∛(a⁴b³c²)-14b∛(ac^(2)) is -6ab∛ac².
What is radical?
The symbol '√' that expresses a root of a number is known as radical and is read as x radical n or nth root of x. The horizontal line covering the number is called the vinculum and the number under it is called the radicand. The number n written before the radical is called the index or degree.
Given radical
8∛(a⁴b³c²)-14b∛(ac^(2))
Rewriting a⁴b³c² as (ab)³ ac²
8∛((ab)³ac²)-14b∛(ac²)
8ab∛ac² - 14b∛ac²
-6ab∛ac².
Hence, -6ab∛ac² is the simplified form of 8∛(a⁴b³c²)-14b∛(ac^(2)).
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Brianna and Ava go to the movie theater and purchase refreshments for their friends. Brianna spends a total of $39.00 on 2 bags of popcorn and 2 drinks. Ava spends a total of $174.50 on 8 bags of popcorn and 10 drinks. Write a system of equations that can be used to find the price of one bag of popcorn and the price of one drink. Using these equations, determine and state the price of a drink, to the nearest cent.
Answer:
2p + 2d = 39 ____________(1)
8p + 10d = 174.50 _________(2)
Price of one drink is $9.25
Step-by-step explanation:
Let the price of a bag of popcorn be p.
Let the price of a drink be d.
Brianna spends a total of $39.00 on 2 bags of popcorn and 2 drinks. This implies that:
2p + 2d = 39 ____________(1)
Ava spends a total of $174.50 on 8 bags of popcorn and 10 drinks. This implies that:
8p + 10d = 174.50 _________(2)
We now have two system of equations which we can use to find the price of a bag of popcorn and drink:
2p + 2d = 39 ____________(1)
8p + 10d = 174.50 _________(2)
Multiply (1) by 4 subtract from (2):
8p + 10d = 174.50 _______(2)
- 8p + 8d = 156 __________(1)
2d = 18.50
=> d = $9.25
The price of one drink is $9.25
What is the length of a diagonal of a cube with a side length of 1 cm?
StartRoot 2 EndRoot cm
StartRoot 3 EndRoot cm
StartRoot 4 EndRoot cm
StartRoot 5 EndRoot cm
Answer:
The answer is 3cm
Step-by-step explanation:
The length of a diagonal of a cube with a side length of 1 cm is,
⇒ √3 cm
What is mean by Multiplication?Multiplication means to add number to itself a particular number of times. Multiply will be viewed as a process of repeated addition.
Given that;
A side length of cube is,
⇒ 1 cm
We know that;
The length of a diagonal of a cube with a side length of a cm is,
⇒ d = √3 × a
Here, a = 1
Hence, The length of a diagonal of a cube with a side length of 1 cm is,
⇒ d = √3 × 1
⇒ d = √3 cm
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