Answers
Answer:
B
Step-by-step explanation:
Use the quadractic equation, x=-b+or-sqrtb^2-4ac/2a, then simplify.
I'm really sorry that it looks messy, I don't know how to make my text look better :(
Related Questions
consider the bevariate data below about Advanced Mathematics and English results for a 2015 examination scored by 14 students in a particular school.The raw score of the examination was out of 100 marks.
Questions:
a)Draw a scatter graph
b)Draw a line of Best Fit
c)Predict the Advance Mathematics mark of a student who scores 30 of of 100 in English.
d)calculate the correlation using the Pearson's Correlation Coefficient Formula
e) Determine the strength of the correlation
Answers
Answer:
Explained below.
Step-by-step explanation:
Enter the data in an Excel sheet.
(a)
Go to Insert → Chart → Scatter.
Select the first type of Scatter chart.
The scatter plot is attached below.
(b)
The scatter plot with the line of best fit is attached below.
The line of best fit is:
[tex]y=-0.8046x+103.56[/tex]
(c)
Compute the value of x for y = 30 as follows:
[tex]y=-0.8046x+103.56[/tex]
[tex]30=-0.8046x+103.56\\\\0.8046x=103.56-30\\\\x=\frac{73.56}{0.8046}\\\\x\approx 91.42[/tex]
Thus, the Advance Mathematics mark of a student who scores 30 out of 100 in English is 91.42.
(d)
The Pearson's Correlation Coefficient is:
[tex]r=\frac{n\cdot \sum XY-\sum X\cdot \sum Y}{\sqrt{[n\cdot \sum X^{2}-(\sum X)^{2}][n\cdot \sum Y^{2}-(\sum Y)^{2}]}}[/tex]
[tex]=\frac{14\cdot 44010-835\cdot 778}{\sqrt{[14\cdot52775-(825)^{2}][14\cdot 47094-(778)^{2}]}}\\\\= -0.7062\\\\\approx -0.71[/tex]
Thus, the Pearson's Correlation Coefficient is -0.71.
(e)
A correlation coefficient between ± 0.50 and ±1.00 is considered as a strong correlation.
The correlation between Advanced Mathematics and English results is -0.71.
This implies that there is a strong negative correlation.
Oregon State University is interested in determining the average amount of paper, in sheets, that is recycled each month. In previous years, the average number of sheets recycled per bin was 59.3 sheets, but they believe this number may have increase with the greater awareness of recycling around campus. They count through 79 randomly selected bins from the many recycle paper bins that are emptied every month and find that the average number of sheets of paper in the bins is 62.4 sheets. They also find that the standard deviation of their sample is 9.86 sheets. What is the value of the test-statistic for this scenario
Answers
Answer:
The test statistic is [tex]t = 2.79[/tex]
Step-by-step explanation:
From the question we are told that
The population mean is [tex]\mu = 59.3[/tex]
The sample size is [tex]n = 79[/tex]
The sample mean is [tex]\= x = 62.4[/tex]
The standard deviation is [tex]\sigma = 9.86[/tex]
Generally the test statistics is mathematically represented as
[tex]t = \frac{\= x - \mu }{ \frac{ \sigma}{ \sqrt{n} } }[/tex]
substituting values
[tex]t = \frac{ 62.2 - 59.3 }{ \frac{ 9.86}{ \sqrt{ 79} } }[/tex]
[tex]t = 2.79[/tex]
Which of the following is an even function? f(x) = (x – 1)2 f(x) = 8x f(x) = x2 – x f(x) = 7
Answers
Answer:
f(x) = 7
Step-by-step explanation:
f(x) = f(-x) it is even
-f(x)=f(-x) it is odd
f(x) = (x – 1)^2 neither even nor odd
f(x) = 8x this is a line odd functions
f(x) = x^2 – x neither even nor odd
f(x) = 7 constant this is an even function
Answer:
answer is f(x)= 7
Step-by-step explanation:
just took edge2020 test
Find all values of x on the graph of f(x) = 2x3 + 6x2 + 7 at which there is a horizontal tangent line.
Answers
Answer:
the equation is not correct, u have to write like
ax'3+bx'2+cx+d
Answer:
x=-2 and x=0
Step-by-step explanation:
So I know it isn't x=-3 and x=0. So my guess is that it is x=0 and x=-2 and heres why.
First, I find the derivative of f(x)=2x^3+6x^2+7 which is 6x^2+12x
Then, I plugged in all the values of x's I had and I found out that you get 0 for -2 and 0 when you plug them in
So, in conclusion I believe the answer to be x=-2 and x=0
A work shift for an employee at Starbucks consists of 8 hours (whole).
What FRACTION (part) of the employees work shift is represented by 2
hours? *
Answers
Answer:
1/4 of an hour
Step-by-step explanation:
2 divided by 8 = 1/4
Answer:
1/4
Step-by-step explanation:
A whole shift is 8 hours
Part over whole is the fraction
2/8
Divide top and bottom by 2
1/4
find the 5th term in the sequence an=n÷n+1
Answers
Answer:
The 5th term of a sequence is defined as the term with n = 5. So for this sequence, a sub 5 = 5/6
Consider the surface f(x,y) = 21 - 4x² - 16y² (a plane) and the point P(1,1,1) on the surface.
Required:
a. Find the gradient of f.
b. Let C' be the path of steepest descent on the surface beginning at P, and let C be the projection of C' on the xy-plane. Find an equation of C in the xy-plane.
c. Find parametric equations for the path C' on the surface.
Answers
Answer:
A) ( -8, -32 )
Step-by-step explanation:
Given function : f (x,y) = 21 - 4x^2 - 16y^2
point p( 1,1,1 ) on surface
Gradient of F
attached below is the detailed solution
A soccer player has made 3 of her last 10 field goals, which is a field goal percentage of 30%. How many more consecutive field goals would she need to make to raise her field goal percentage to 50%?
Answers
Answer:
4 consecutive goals
Step-by-step explanation:
If 3 of last 10 field goals = 30%
Which is equivalent to
(Number of goals scored / total games played) * 100%
(3 / 10) * 100% = 30%
Number of consecutive goals one has to score to raise field goal to 50% will be:
Let y = number of consecutive goals
[(3+y) / (10+y)] * 100% = 50%
[(3+y) / (10+y)] * 100/100 = 50/100
[(3+y) / (10+y)] * 1 = 0.5
(3+y) / (10+y) = 0.5
3+y = 0.5(10 + y)
3+y = 5 + 0.5y
y - 0.5y = 5 - 3
0.5y = 2
y = 2 / 0.5
y = 4
Therefore, number of consecutive goals needed to raise field goal to 50% = 4
Let f(x) = x - 1 and g(x) = x^2 - x. Find and simplify the expression. (f + g)(1) (f +g)(1) = ______
Answers
Answer:
The simplified answer of the given expression is 1.
Step-by-step explanation:
When you see (f + g)(x), then it means that you are going to add f(x) and g(x) together. So, we are going to add the terms together that are given in the problem. We are also given the value of x which is 1. So, we are going to combine this information together so we can simplify the expression.
(f + g)(1)
f(x) = x - 1
g(x) = x²
(f + g)(1) = (1 - 1) + (1²)
Simplify the terms in the parentheses.
(f + g)(1) = 0 + 1
Add 0 and 1.
(f + g)(1) = 1
So, (f + g)(1) will have a simplified answer of 1.
99 litres of gasoline oil is poured into a cylindrical drum of 60cm in diameter. How deep is the oil in the drum?
Answers
Answer:
35 cm
Step-by-step explanation:
The volume of a cylinder is given by ...
V = πr²h
We want to find h for the given volume and diameter. First, we must convert the given values to compatible units.
1 L = 1000 cm³, so 99 L = 99,000 cm³
60 cm diameter = 2 × 30 cm radius
So, we have ...
99,000 cm³ = π(30 cm)²h
99,000/(900π) cm = h ≈ 35.01 cm
The oil is 35 cm deep in the drum.
For a certain instant lottery game, the odds in favor of a win are given as 81 to 19. Express the indicated degree of likelihood as a probability value between 0 and 1 inclusive.
Answers
Answer: 0.81
Step-by-step explanation:
[tex]81:19\ \text{can be written as the fraction}\ \dfrac{81}{81+19}=\dfrac{81}{100}=\large\boxed{0.81}[/tex]
find the range of the inequality 2e-3< 3e-1
Answers
Answer:
[tex]x = { - 1, 0,1 ,2 ...}[/tex]
Step-by-step explanation:
[tex]2e - 3 < 3e - 1 = 2e - 3e < - 1 + 3 = - 1e < 2 = e > - 2[/tex]
Hope this helps ;) ❤❤❤
evaluate the expression 4x^2-6x+7 if x = 5
Answers
Answer:
77
Step-by-step explanation:
4x^2-6x+7
Let x = 5
4* 5^2-6*5+7
4 * 25 -30 +7
100-30+7
7-+7
77
Find the solution of the inequality 5 > r - 3.
A) r<2
B) r = 2
C) r=8
(D) r < 8
Answers
Answer:
[tex]\huge\boxed{r<8}[/tex]
Step-by-step explanation:
[tex]5 > r - 3[/tex]
Adding 3 to both sides
[tex]5 + 3 > r[/tex]
[tex]8 > r\\OR \\r < 8[/tex]
Answer: D. r<8
Step-by-step explanation:
[tex]5>r-3[/tex]
add 3 to both sides
[tex]r-3+3<5+3[/tex]
[tex]5+3=8[/tex]
simplify
[tex]r<8[/tex]
anyone can help me with these questions?
please gimme clear explanation :)
Answers
Step-by-step explanation:
The limit of a function is the value it approaches.
In #37, as x approaches infinity (far to the right), the curve f(x) approaches 1. As x approaches negative infinity (far to the left), the curve f(x) approaches -1.
lim(x→∞) f(x) = 1
lim(x→-∞) f(x) = -1
In #38, as x approaches infinity (far to the right), the curve f(x) approaches 2. As x approaches negative infinity (far to the left), the curve f(x) approaches -3.
lim(x→∞) f(x) = 2
lim(x→-∞) f(x) = -3
g A random sample of size 16 taken from a normally distributed population revealed a sample mean of 50 and a sample variance of 36. The upper limit of a 95% confidence interval for the population mean would equal:
Answers
Answer:
The upper limit is
[tex]k = 52.94[/tex]
Step-by-step explanation:
From the question we told that
The sample size is [tex]n = 16[/tex]
The sample mean is [tex]\= x = 50[/tex]
The sample variance is [tex]\sigma ^2 = 36[/tex]
For a 95% confidence interval the confidence level is 95%
Given that the confidence level is 95% then the level of significance is mathematically evaluated as
[tex]\alpha = 100 - 95[/tex]
[tex]\alpha = 5 \%[/tex]
[tex]\alpha = 0.05[/tex]
Next we obtain the critical value of [tex]\frac{\alpha }{2}[/tex] from the normal distribution table(reference- math dot armstrong dot edu), the value is
[tex]Z_{\frac{ \alpha }{2} } = 1.96[/tex]
Generally the margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \frac{\sigma}{\sqrt{n} }[/tex]
Here [tex]\sigma[/tex] is the standard deviation which is mathematically evaluated as
[tex]\sigma = \sqrt{\sigma^2}[/tex]
substituting values
[tex]\sigma = \sqrt{36}[/tex]
=> [tex]\sigma = 6[/tex]
So
[tex]E = 1.96 * \frac{6}{\sqrt{16} }[/tex]
[tex]E = 2.94[/tex]
The 95% confidence interval is mathematically represented as
[tex]\= x - E < \mu < \= x + E[/tex]
substituting values
[tex]50 -2.94 < \mu <50 +2.94[/tex]
[tex]47.06 < \mu <52.94[/tex]
The upper limit is
[tex]k = 52.94[/tex]
Please answer this correctly without making mistakes
Answers
Answer:
355/12
Step-by-step explanation:
Answer:
355/12mi
Step-by-step explanation:
9 1/2 = 19/2
20 1/12 = 241/12
19/2 + 241/12 = 355/12mi
A normal distribution has a mean of 30 and a variance of 5.Find N such that the probability that the mean of N observations exceeds 30.5 is 1%.
Answers
Answer:
109
Step-by-step explanation:
Use a chart or calculator to find the z-score corresponding to a probability of 1%.
P(Z > z) = 0.01
P(Z < z) = 0.99
z = 2.33
Now find the sample standard deviation.
z = (x − μ) / s
2.33 = (30.5 − 30) / s
s = 0.215
Now find the sample size.
s = σ / √n
s² = σ² / n
0.215² = 5 / n
n = 109
What is 5 feet and 11 inches in inches
Answers
Answer:
60
Step-by-step explanation:
5 is 60 inch
Choose the algebraic description that maps ΔABC onto ΔA′B′C′ in the given figure. Question 9 options:
A) (x, y) → (x, y – 6)
B) (x, y) → (x – 6, y)
C) (x, y) → (x, y + 6)
D) (x, y) → (x + 6, y)
Answers
Answer:
B) (x, y) → (x – 6, y)
Step-by-step explanation:
Each x-value in the image is 6 less than in the pre-image. Each y-value is the same. That means x gets mapped to x-6, and y gets mapped to y:
(x, y) → (x – 6, y)
Please Solve
F/Z=T for Z
Answers
Answer:
F /T = Z
Step-by-step explanation:
F/Z=T
Multiply each side by Z
F/Z *Z=T*Z
F = ZT
Divide each side by T
F /T = ZT/T
F /T = Z
Answer:
[tex]\boxed{\red{ z = \frac{f}{t} }}[/tex]
Step-by-step explanation:
[tex] \frac{f}{z} = t \\ \frac{f}{z} = \frac{t}{1} \\ zt = f \\ \frac{zt}{t} = \frac{f}{t} \\ z = \frac{f}{t} [/tex]
If f(x) = 2x2 – 3x – 1, then f(-1)=
Answers
Given:f(x)=2x^2-3x-1
Then,f(-1)=2(-1)^2-3(-1)-1
f(-1)=2(1)+3-1
f(-1)=5-1
f(-1)=4
HOPE IT HELPS!!!!!!
PLEASE MARK BRAINLIEST!!!!!
The value of function at x= -1 is f(-1) = 4.
We have the function as
f(x) = 2x² - 3x -1
To find the value of f(-1) when f(x) = 2x² - 3x -1, we substitute x = -1 into the expression:
f(-1) = 2(-1)² - 3(-1) - 1
= 2(1) + 3 - 1
= 2 + 3 - 1
= 4.
Therefore, the value of function at x= -1 is f(-1) = 4.
Learn more about Function here:
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The odds in favor of a horse winning a race are 7:4. Find the probability that the horse will win the race.
Answers
Answer:
7/11 = 0.6363...
Step-by-step explanation:
7 + 4 = 11
probability of winning: 7/11 = 0.6363...
The probability that the horse will in the race is [tex]\mathbf{\dfrac{7}{11}}[/tex]
Given that the odds of the horse winning the race is 7:4
Assuming the ratio is in form of a:b, the probability of winning the race can be computed as:
[tex]\mathbf{P(A) = \dfrac{a}{a+b}}[/tex]
From the given question;
The probability of the horse winning the race is:
[tex]\mathbf{P(A) = \dfrac{7}{7+4}}[/tex]
[tex]\mathbf{P(A) = \dfrac{7}{11}}[/tex]
Learn more about probability here:
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AB is dilated from the origin to create A'B' at A' (0, 8) and B' (8, 12). What scale factor was AB dilated by?
Answers
Answer:
4
Step-by-step explanation:
Original coordinates:
A (0, 2)
B (2, 3)
The scale is what number the original coordinates was multiplied by to reach the new coordinates
1. Divide
(0, 8) ÷ (0, 2) = 4
(8, 12) ÷ (2, 3) = 4
AB was dilated by a scale factor of 4.
A survey asked, "How many tattoos do you currently have on your body?" Of the males surveyed, responded that they had at least one tattoo. Of the females surveyed, responded that they had at least one tattoo. Construct a % confidence interval to judge whether the proportion of males that have at least one tattoo differs significantly from the proportion of females that have at least one tattoo. Interpret the interval.
Answers
Complete Question
The complete question is shown on the first uploaded image
Answer:
The 95% interval for [tex]p_1 - p_2[/tex] is [tex]-0.0171 ,0.0411[/tex]
Option A is correct
Step-by-step explanation:
From the question we are told that
The sample size of male is [tex]n_1 = 1211[/tex]
The number of males that said they have at least one tattoo is [tex]r = 182[/tex]
The sample size of female is [tex]n_2 = 1041[/tex]
The number of females that said they have at least one tattoo is [tex]k = 144[/tex]
Generally the sample proportion of male is
[tex]\r p_1 = \frac{r}{ n_1}[/tex]
substituting values
[tex]\r p_1 = \frac{ 182}{1211}[/tex]
[tex]\r p_1 = 0.1503[/tex]
Generally the sample proportion of female is
[tex]\r p_2 = \frac{k}{ n_2}[/tex]
substituting values
[tex]\r p_2 = \frac{ 144}{1041}[/tex]
[tex]\r p_2 = 0.1383[/tex]
Given that the confidence level is 95% then the level of significance is mathematically represented as
[tex]\alpha =100-95[/tex]
[tex]\alpha =5\%[/tex]
[tex]\alpha =0.05[/tex]
Next we 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 margin of error is mathematically represented as
[tex]E = Z_{\frac{\alpha }{2} } * \sqrt{\frac{\r p_1 (1- \r p_1)}{n_1} + \frac{\r p_2 (1- \r p_2)}{n_2} }[/tex]
substituting values
[tex]E = 1.96 * \sqrt{\frac{ 0.1503 (1- 0.1503)}{1211} + \frac{0.1383 (1- 0.1383)}{1041} }[/tex]
[tex]E = 0.0291[/tex]
The 95% confidence interval is mathematically represented as
[tex](\r p_1 - \r p_2 ) - E < p_1-p_2 < (\r p_1 - \r p_2 ) + E[/tex]
substituting values
[tex](0.1503- 0.1383 ) - 0.0291 < p_1-p_2 < (0.1503- 0.1383 ) + 0.0291[/tex]
[tex]-0.0171 < p_1-p_2 < 0.0411[/tex]
So the interpretation is that there is 95% confidence that the difference of the proportion is in the interval .So conclude that there is insufficient evidence of a significant difference in the proportion of male and female that have at least one tattoo
This because the difference in proportion is less than [tex]\alpha[/tex]
Figure out if the figure is volume or surface area.
(and the cut out cm is 4cm)
Answers
Answer:
Surface area of the box = 168 cm²
Step-by-step explanation:
Amount of cardboard needed = Surface area of the box
Since the given box is in the shape of a triangular prism,
Surface area of the prism = 2(surface area of the triangular bases) + Area of the three rectangular lateral sides
Surface area of the triangular base = [tex]\frac{1}{2}(\text{Base})(\text{height})[/tex]
= [tex]\frac{1}{2}(6)(4)[/tex]
= 12 cm²
Surface area of the rectangular side with the dimensions of (6cm × 9cm),
= Length × width
= 6 × 9
= 54 cm²
Area of the rectangle with the dimensions (9cm × 5cm),
= 9 × 5
= 45 cm²
Area of the rectangle with the dimensions (9cm × 5cm),
= 9 × 5
= 45 cm²
Surface area of the prism = 2(12) + 54 + 45 + 45
= 24 + 54 + 90
= 168 cm²
What is the value of the product (3 – 2i)(3 + 2i)?
Answers
Answer:
13
Step-by-step explanation:
(3 - 2i)(3 + 2i)
Expand
(9 + 6i - 6i - 4i^2)
Add
(9 - 4i^2)
Convert i^2
i^2 = ([tex]\sqrt{-1}[/tex])^2 = -1
(9 - 4(-1))
Add
(9 + 4)
= 13
Answer:
13.
Step-by-step explanation:
(3 - 2i)(3 + 2i)
= (3 * 3) + (-2i * 3) + (2i * 3) + (-2i * 2i)
= 9 - 6i + 6i - 4[tex]\sqrt{-1} ^{2}[/tex]
= 9 - 4(-1)
= 9 + 4
= 13
Hope this helps!
2/5 ( 1/3 x− 15/8 )− 1/3 ( 1/2 − 2/3 x)
Answers
Answer:
16/45x-11/12
Step-by-step explanation:
Multiply across
2/15x-30/40-1/6+2/9x=
Get common denominators of like terms
6/45x+10/45x-9/12-2/12=
Combine like terms
16/45x-11/12
The simplified expression is: (16/45)x - (11/12)
To simplify the given expression, we'll follow the steps:
Step 1: Distribute the fractions through the parentheses.
Step 2: Simplify the expression by combining like terms.
Let's proceed with the simplification:
Step 1: Distribute the fractions through the parentheses:
2/5 * (1/3x - 15/8) - 1/3 * (1/2 - 2/3x)
Step 2: Simplify the expression:
To distribute 2/5 through (1/3x - 15/8):
2/5 * 1/3x = 2/15x
2/5 * (-15/8) = -15/20 = -3/4
So, the first part becomes: 2/15x - 3/4
To distribute -1/3 through (1/2 - 2/3x):
-1/3 * 1/2 = -1/6
-1/3 * (-2/3x) = 2/9x
So, the second part becomes: -1/6 + 2/9x
Now, the entire expression becomes:
2/15x - 3/4 - 1/6 + 2/9x
Step 3: Combine like terms:
To combine the terms with "x":
2/15x + 2/9x = (2/15 + 2/9)x
Now, find the common denominator for (2/15) and (2/9), which is 45:
(2/15 + 2/9) = (6/45 + 10/45) = 16/45
So, the combined x term becomes:
(16/45)x
Now, combine the constant terms:
-3/4 - 1/6 = (-18/24 - 4/24) = -22/24
To simplify -22/24, we can divide both numerator and denominator by their greatest common divisor (which is 2):
-22 ÷ 2 = -11
24 ÷ 2 = 12
So, the combined constant term becomes:
(-11/12)
Putting it all together, the simplified expression is:
(16/45)x - (11/12)
To know more about expression:
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Complete question is:
Simplify the given expression: 2/5 ( 1/3 x− 15/8 )− 1/3 ( 1/2 − 2/3 x)
You are going to your first school dance! You bring $20,
and sodas cost $2. How many sodas can you buy?
Please write and solve an equation (for x sodas), and
explain how you set it up.
Answers
Answer:
10
Step-by-step explanation:
Let the no. of sodas be x
Price of each soda = $2
Therefore, no . of sodas you can buy = $2x
2x=20
=>x=[tex]\frac{20}{2}[/tex]
=>x=10
you can buy 10 sodas
Answer: 10 sodas
Step-by-step explanation:
2x = 20 Divide both sides by 2
x = 10
If I brought 20 dollars and I want to by only sodas and each sodas cost 2 dollars, then I will divide the total amount of money that I brought by 2 to find out how many sodas I could by.
A fair die is tossed once, what is the probability of obtaining neither 5 nor 2?
Answers
Answer:
4/6 or 66.666...%
Step-by-step explanation:
If you want to find the probability of obtaining neither a 5 nor a 2 you find how many times they occur and add them together in this case 5 occurs once and 2 also occurs once out of 6 numbers so 1/6 + 1/6 equals 2/6, you now know that 4/6 of them won't be a 5 nor a 2 and because it is a fair die the likelihood of it falling on a number is the same for all sides so the answer is 4/6 or 66.67%.
