Answer:
(1) B
(2) A
(3) C
Step-by-step explanation:
A random variable is a variable that denotes a set of all the possible outcomes of a random experiment. It is denotes by a single capital letter such as X or Y.
There are two types of random variables.
Discrete random variable: These type of random variable takes finite number of values, such as 0, 1, 2, 3, 4, ... For example, number of girl child in a neighborhood.Continuous random variable: These type of random variables takes infinite number of possible values. For example, the height, weight.(1)
Exact weight of quarters now in circulation in the United States.
The variable weight is a continuous variable.
Thus, the exact weight of quarters now in circulation in the United States is a continuous random variable.
(2)
Shoe sizes of humans.
The shoe size of a person are discrete and finite values.
Thus, the shoe sizes of humans are discrete random variables.
(3)
Political party affiliations of adults in the United States.
This variable is not a quantitative variable.
It is a qualitative variable.
Thus, the political party affiliations of adults in the United States is no random variable.
Figure out if the figure is volume or surface area.
(and the cut out cm is 4cm)
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
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:
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]
Simplify . 7+ the square root of 6(3+4)-2+9-3*2^2 The solution is
Answer:
7+sqrt(37)
Step-by-step explanation:
7+sqrt(6*(3+4)-2+9-3*2^2)=7+sqrt(6*7+7-3*4)=7+sqrt(42+7-12)=7+sqrt(37)
Which of the following is an even function? f(x) = (x – 1)2 f(x) = 8x f(x) = x2 – x f(x) = 7
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
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
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.
anyone can help me with these questions?
please gimme clear explanation :)
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
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?
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.
Researchers recorded that a certain bacteria population declined from 450,000 to 900 in 30 hours at this rate of decay how many bacteria will there be in 13 hours
Answer:
30,455
Step-by-step explanation:
Exponential decay
y = a(1 - b)^x
y = final amount
a = initial amount
b = rate of decay
x = time
We are looking for the rate of decay, b.
900 = 450000(1 - b)^30
1 = 500(1 - b)^30
(1 - b)^30 = 0.002
1 - b = 0.002^(1/30)
1 - b = 0.81289
b = 0.1871
The equation for our case is
y = 450000(1 - 0.1871)^x
We are looking for the amount in 13 hours, so x = 13.
y = 450000(1 - 0.1871)^13
y = 30,455
Let f(x) = x - 1 and g(x) = x^2 - x. Find and simplify the expression. (f + g)(1) (f +g)(1) = ______
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.
Please answer this correctly without making mistakes
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 fair die is tossed once, what is the probability of obtaining neither 5 nor 2?
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%.
Evaluate integral _C x ds, where C is
a. the straight line segment x = t, y = t/2, from (0, 0) to (12, 6)
b. the parabolic curve x = t, y = 3t^2, from (0, 0) to (2, 12)
Answer:
a. [tex]\mathbf{36 \sqrt{5}}[/tex]
b. [tex]\mathbf{ \dfrac{1}{108} [ 145 \sqrt{145} - 1]}}[/tex]
Step-by-step explanation:
Evaluate integral _C x ds where C is
a. the straight line segment x = t, y = t/2, from (0, 0) to (12, 6)
i . e
[tex]\int \limits _c \ x \ ds[/tex]
where;
x = t , y = t/2
the derivative of x with respect to t is:
[tex]\dfrac{dx}{dt}= 1[/tex]
the derivative of y with respect to t is:
[tex]\dfrac{dy}{dt}= \dfrac{1}{2}[/tex]
and t varies from 0 to 12.
we all know that:
[tex]ds=\sqrt{ (\dfrac{dx}{dt})^2 + ( \dfrac{dy}{dt} )^2}} \ \ dt[/tex]
∴
[tex]\int \limits _c \ x \ ds = \int \limits ^{12}_{t=0} \ t \ \sqrt{1+(\dfrac{1}{2})^2} \ dt[/tex]
[tex]= \int \limits ^{12}_{0} \ \dfrac{\sqrt{5}}{2}(\dfrac{t^2}{2}) \ dt[/tex]
[tex]= \dfrac{\sqrt{5}}{2} \ \ [\dfrac{t^2}{2}]^{12}_0[/tex]
[tex]= \dfrac{\sqrt{5}}{4}\times 144[/tex]
= [tex]\mathbf{36 \sqrt{5}}[/tex]
b. the parabolic curve x = t, y = 3t^2, from (0, 0) to (2, 12)
Given that:
x = t ; y = 3t²
the derivative of x with respect to t is:
[tex]\dfrac{dx}{dt}= 1[/tex]
the derivative of y with respect to t is:
[tex]\dfrac{dy}{dt} = 6t[/tex]
[tex]ds = \sqrt{1+36 \ t^2} \ dt[/tex]
Hence; the integral _C x ds is:
[tex]\int \limits _c \ x \ ds = \int \limits _0 \ t \ \sqrt{1+36 \ t^2} \ dt[/tex]
Let consider u to be equal to 1 + 36t²
1 + 36t² = u
Then, the differential of t with respect to u is :
76 tdt = du
[tex]tdt = \dfrac{du}{76}[/tex]
The upper limit of the integral is = 1 + 36× 2² = 1 + 36×4= 145
Thus;
[tex]\int \limits _c \ x \ ds = \int \limits _0 \ t \ \sqrt{1+36 \ t^2} \ dt[/tex]
[tex]\mathtt{= \int \limits ^{145}_{0} \sqrt{u} \ \dfrac{1}{72} \ du}[/tex]
[tex]= \dfrac{1}{72} \times \dfrac{2}{3} \begin {pmatrix} u^{3/2} \end {pmatrix} ^{145}_{1}[/tex]
[tex]\mathtt{= \dfrac{2}{216} [ 145 \sqrt{145} - 1]}[/tex]
[tex]\mathbf{= \dfrac{1}{108} [ 145 \sqrt{145} - 1]}}[/tex]
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%.
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 the value of the product (3 – 2i)(3 + 2i)?
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!
The odds in favor of a horse winning a race are 7:4. Find the probability that the horse will win the race.
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:
https://brainly.com/question/11234923?referrer=searchResults
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)
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)
If f(x) = 2x2 – 3x – 1, then f(-1)=
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:
https://brainly.com/question/32020999
#SPJ6
Find all values of x on the graph of f(x) = 2x3 + 6x2 + 7 at which there is a horizontal tangent line.
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
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.
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
evaluate the expression 4x^2-6x+7 if x = 5
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
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
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]
99 litres of gasoline oil is poured into a cylindrical drum of 60cm in diameter. How deep is the oil in the drum?
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.
A raffle offers one $8000.00 prize, one $4000.00 prize, and five $1600.00 prizes. There are 5000 tickets sold at $5 each. Find the expectation if a person buys one ticket.
Answer:
The expectation is [tex]E(1 )= -\$ 1[/tex]
Step-by-step explanation:
From the question we are told that
The first offer is [tex]x_1 = \$ 8000[/tex]
The second offer is [tex]x_2 = \$ 4000[/tex]
The third offer is [tex]\$ 1600[/tex]
The number of tickets is [tex]n = 5000[/tex]
The price of each ticket is [tex]p= \$ 5[/tex]
Generally expectation is mathematically represented as
[tex]E(x)=\sum x * P(X = x )[/tex]
[tex]P(X = x_1 ) = \frac{1}{5000}[/tex] given that they just offer one
[tex]P(X = x_1 ) = 0.0002[/tex]
Now
[tex]P(X = x_2 ) = \frac{1}{5000}[/tex] given that they just offer one
[tex]P(X = x_2 ) = 0.0002[/tex]
Now
[tex]P(X = x_3 ) = \frac{5}{5000}[/tex] given that they offer five
[tex]P(X = x_3 ) = 0.001[/tex]
Hence the expectation is evaluated as
[tex]E(x)=8000 * 0.0002 + 4000 * 0.0002 + 1600 * 0.001[/tex]
[tex]E(x)=\$ 4[/tex]
Now given that the price for a ticket is [tex]\$ 5[/tex]
The actual expectation when price of ticket has been removed is
[tex]E(1 )= 4- 5[/tex]
[tex]E(1 )= -\$ 1[/tex]
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.
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.
Which function below has the following domain and range?
Domain: { -6, -5,1,2,6}
Range: {2,3,8)
{(2,3), (-5,2), (1,8), (6,3), (-6, 2)
{(-6,2), (-5,3), (1,8), (2,5), (6,9)}
{(2,-5), (8, 1), (3,6), (2, - 6), (3, 2)}
{(-6,6), (2,8)}
Answer:
{(2,3), (-5,2), (1,8), (6,3), (-6, 2)
Step-by-step explanation:
The domain is the input and the range is the output
We need inputs of -6 -5 1 2 6
and outputs of 2 3 and 8
Which graph shows the polar coordinates (-3,-) plotted
Brainliest! Jared uses the greatest common factor and the distributive property to rewrite this sum: 100 + 75 Drag one number into each box to show Jared's expression. Brainliest!
Answer:
25(4 + 3)
Step-by-step explanation:
100 = 2^2 + 5^2
75 = 3 * 5^2
GCF = 5^2 = 25
100 + 75 =
= 25 * 4 + 25 * 3
= 25(4 + 3)
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.
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]
Please Solve
F/Z=T for Z
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]
solve the equation
Answer:
x = 10
Step-by-step explanation:
2x/3 + 1 = 7x/15 + 3
(times everything in the equation by 3 to get rid of the first fraction)
2x + 3 = 21x/15 + 9
(times everything in the equation by 15 to get rid of the second fraction)
30x+ 45 = 21x + 135
(subtract 21x from 30x; subtract 45 from 135)
9x = 90
(divide 90 by 9)
x = 10
Another solution:
2x/3 + 1 = 7x/15 + 3
(find the LCM of 3 and 15 = 15)
(multiply everything in the equation by 15, then simplify)
10x + 15 = 7x + 45
(subtract 7x from 10x; subtract 15 from 45)
3x = 30
(divide 30 by 3)
x = 10
