The notation f:S→T denotes that f is a function, also called a map , defined on all of a set S and whose outputs lie in a set T . A function f:S→T is injective if for all x,y∈S , f(x)=f(y) implies that x=y . Alternatively: a function is injective if we can uniquely recover some input x based on an output f(x) . What functions are injective?
Answer:
There are many. Two examples are
[tex]f(x) = x, \\f(x) = x^3[/tex]
Step-by-step explanation:
There are many examples. The simplest is
1 -
[tex]f(x) = x[/tex]
It is trivial that
[tex]\text{if \,\,\,\,} f(x) = f(y) \,\,\,\,\,\text{then} \,\,\,\,\, x=y[/tex]
2 -
[tex]f(x) = x^3[/tex]
That function is injective as well.
[tex]\text{if \,\,\,\,} x^3 = y^3 \,\,\,\,\,\text{then} \,\,\,\,\, x=y[/tex]
An example of a function that is NOT injective is
[tex]f(x) = x^2[/tex]
Notice that
[tex]f(-2) = (-2)^2 = 2^2 = 4[/tex]
A gun mass of 5 kg fired a bullet of mass 10 g with the velocity of 360 km/h. What
is gun’s velocity of pushing behind?
answer fast please
Answer:
The recoil velocity of the gun is [tex]0.72\,\,\frac{km}{h}[/tex] and is pointing in opposite direction to the velocity of the bullet.
Step-by-step explanation:
Use conservation of linear momentum, which states that the momentum of the bullet (product of the bullet's mass times its speed) should equal in absolute value the momentum of the recoiling gun (its mass times its recoil velocity).
We also write the mass of the bullet in the same units as the mass of the gun (for example kilograms). Mass of the bullet = 0.010 kg
In mathematical terms, we have:
[tex]5\, kg * v= 0.01 \,kg\,* 360\,\frac{km}{h} \\v=\frac{0.01\,*360}{5} \,\,\frac{km}{h}\\v=0.72\,\,\frac{km}{h}[/tex]
question is attached
I apologize, I am stumped... I thought you would find either the centroid, circumcenter, or incenter of the triangle created but it didn't work quite right for me.
For the following report about a statistical study, identify the items below.
To find the public’s views on pollution, researchers waited outside a car dealership they had randomly selected from a list of such establishments. They stopped every 10th person who came out of the dealership and asked whether he or she thought pollution was a serious problem.
A) The population...
B) The population parameter of interest..
C) The sampling frame...
D) The sample...
E) The sampling method, including whether or not randomization was employed...
F) Any potential sources of bias you can detect and any problems you see in generalizing to the population of interest...
Answer:
Check Explanation
Step-by-step explanation:
In finding the public's view on pollution, the researchers waited outside a car dealership they had randomly selected from a list of such establishments. They stopped every 10th person who came out of the dealership and asked whether he or she thought pollution was a serious problem.
A) The population
The population is the sum total of every member of the public whose opinions on pollution, the researchers are interested in.
B) The population parameter of interest
Since the researchers stopped every member of the sample to ask them whether they thought pollution was a serious problem or not, it follows that the population parameter of interest is the proportion of the population who think that pollution is a serious problem.
C) The sampling frame
The sampling frame is defined as the source material where the sample is drawn from. And for this question, the sampling frame is the population of people leaving car dealership establishments.
D) The sample
The sample is the set of people that were asked the question of whether population was a serious problem or not. The sample includes every 10th person that came out of the chosen car dealership establishments.
E) The sampling method
Note that
- In random sampling, each population member would have an equal chance of being surveyed.
- Stratified sampling divides the population into groups called strata. A sample is taken from some or all of these strata using either random, systematic, or convenience sampling.
- In systematic sampling, a particular number, n, is counted repeatedly and each of the nth member is picked to be sampled.
Hence, this stratified sampling method uses random sampling technique to pick the strata where the samples will be obtained from and systematic sampling is now used for the picking of the members of the sample.
F) Any potential sources of bias you can detect and any problems you see in generalizing to the population of interest.
This survey only limits the members of the sample to those who visit a car dealership, and this cuts out a large percentage of the total population of humans.
Mostly men visit car dealership establishments, Hence, women, children, old people are at a disadvantage as they do not all have an equal chance of being surveyed.
Infact, only a financial class of the population visits car dealership establishments, so, it would be very wrong with all of this bias to use the results of this surveyor generalize for the whole population of people.
Hope this Helps!!!
What one is it I have have been struggling with this
Answer:
C is the correct answer.
Step-by-step explanation:
The reason it is C is because pi/the symbol on top is irrational.
Hope you have a good rest of your day :)
Of the mathematics degrees awarded in recent years, 76% were bachelor’s degrees, 21% were master’s degrees and the remaining 3% were doctorates. Moreover, women earned 52% of bachelors, 40% of masters and 22% of doctorates. What is the probability that a randomly chosen mathematics degree was a master's degree given that it was awarded to a woman? Give your answer to 4 decimal places.
Answer:
0.1729 = 17.29% probability that a randomly chosen mathematics degree was a master's degree given that it was awarded to a woman
Step-by-step explanation:
Bayes Theorem:
Two events, A and B.
[tex]P(B|A) = \frac{P(B)*P(A|B)}{P(A)}[/tex]
In which P(B|A) is the probability of B happening when A has happened and P(A|B) is the probability of A happening when B has happened.
In this question:
Event A: Given to a woman.
Event B: Masters degree.
21% were master’s degrees
This means that [tex]P(B) = 0.21[/tex]
Women earned 40% of masters
This means that [tex]P(A|B) = 0.4[/tex]
Probability of the degree being given to a women:
52% of 76%, 40% of 21% and 22% of 3%. So
[tex]P(A) = 0.52*0.76 + 0.4*0.21 + 0.22*0.03 = 0.4858[/tex]
What is the probability that a randomly chosen mathematics degree was a master's degree given that it was awarded to a woman?
[tex]P(B|A) = \frac{0.21*0.4}{0.4858} = 0.1729[/tex]
0.1729 = 17.29% probability that a randomly chosen mathematics degree was a master's degree given that it was awarded to a woman
What single decimal multiplier would you use to increase by 7% followed by a 4% decrease?
Answer: To increase an amount by 7%, you would want to use 1.07 as the multiplier. To decrease it, you would use 0.93
Step-by-step explanation:
Which data collection method would provide an unbiased sample?
Answer:
The best data collection method or sampling method to provide an unbiased sample is the random sampling method.
Step-by-step explanation:
There are 5 popular known sampling methods or data collection methods.
1) Random Sampling
In random sampling, each member of the population would have an equal chance of being surveyed. One of the best ways to use random sampling is to give all the members of the population numbers and then use computer to generate random numbers and pick the members of the population with those random numbers.
2) Systematic sampling is easier than random sampling. In systematic sampling, a particular number, n, is counted repeatedly and each of the nth member is picked to be sampled.
3) Convenience Sampling
This is the worst sampling technique. It is also the easiest. In Convenience sampling, the surveyor just picks the first set of members of the population that they find and surveys.
4) Stratified Sampling
Stratified sampling divides the population into groups called strata. A sample is taken from each of these strata using either random, systematic, or convenience sampling.
5) Cluster sampling
Cluster Sampling divides the population into groups which are called clusters or blocks. The clusters are selected randomly, and some members or every element/member in the selected clusters is surveyed.
Hope this Helps!!!
The base diameter and the height of a cone are both equal to
x units.
Which expression represents the volume of the cone, in
cubic units?
pix2
2pix3
1/3pix2
1/12pix3
Answer:
[tex]\frac{\pi x^3}{3}[/tex]
Step-by-step explanation:
[tex]V=\pi r^2h\frac{1}{3}[/tex]
[tex]V=\pi x^2x\frac{1}{3}[/tex]
[tex]V=\pi x^3\frac{1}{3}[/tex]
[tex]V=\frac{\pi x^3}{3}[/tex]
[tex]V=1.047198x^3[/tex]
Answer:
Step-by-step explanation:
1/12 pi x ^3
Lydia is going to invest $210 and leave it in an account for 17 years. Assuming the interest is compounded daily, what interest rate, to the nearest hundredth of a percent, would be required in order for Lydia to end up with $330?
Answer:
To the nearest hundredth of a percentage= 0.03
Step-by-step explanation:
Formula for compound interest
A= p(1+r/n)^nt
A= $330
P= $210
n = 356
t= 17
r = ?
330 = 210(1+r/356)^(356*17)
330 = 210(1+r/356)^(6052)
330/210 = (1+r/356)^6052
(6052√(330/210) - 1 )356 = r
(1.000074686-1)356= r
0.02658 = r
To the nearest hundredth of a percentage= 0.03
Answer:
2.66
Step-by-step explanation:
Describe the rule for the sequence 2, 1, 2/3, 1/2, 2/5, 1/3, 1/7,...
Multiply 2 by 1/2 to get 1.
Multiply 1 by 2/3 to get 2/3.
Multiply 2/3 by 3/4 to get 6/12 = 1/2.
Multiply 1/2 by 4/5 to get 4/10 = 2/5.
Multiply 2/5 by 5/6 to get 10/30 = 1/3.
Multiply 1/3 by 6/7 to get 6/21 = 2/7. (I suspect there's a typo in the question.)
And so on, so that the nth term in the sequence is multiplied by n/(n + 1) to get the (n + 1)th term.
Recursively, the sequence is given by
[tex]\begin{cases}a_1=2\\a_n=\dfrac{n-1}na_{n-1}&\text{for }n>1\end{cases}[/tex]
We can solve this exactly by iterating:
[tex]a_n=\dfrac{n-1}na_{n-1}=\dfrac{n-1}n\dfrac{n-2}na_{n-1}=\dfrac{n-1}n\dfrac{n-2}{n-1}\dfrac{n-3}{n-2}a_{n-3}=\cdots[/tex]
and so on down to
[tex]a_n=\dfrac{(n-1)\cdot(n-2)\cdot(n-3)\cdot\cdots\cdot3\cdot2\cdot1}{n\cdot(n-1)\cdot(n-2)\cdot\cdots\cdot4\cdot3\cdot2}a_1[/tex]
or
[tex]a_n=\dfrac{(n-1)!}{n!}a_1[/tex]
and with lots of cancellation, we end up with
[tex]a_n=\dfrac{a_1}n=\boxed{\dfrac2n}[/tex]
Answer:
Divide 2 by n.
Step-by-step explanation:
Someone claims that the breaking strength of their climbing rope is 2,000 psi, with a standard deviation of 10 psi. We think the actual amount is lower than that and want to run the test at an alpha level of 5%. What would our sample size need to be if we want to reject the null hypothesis if the sample mean is at or below 1,997.2956?
Answer:
The sample size must be greater than 37 if we want to reject the null hypothesis.
Step-by-step explanation:
We are given that someone claims that the breaking strength of their climbing rope is 2,000 psi, with a standard deviation of 10 psi.
Also, we are given a level of significance of 5%.
Let [tex]\mu[/tex] = mean breaking strength of their climbing rope
SO, Null Hypothesis, [tex]H_0[/tex] : [tex]\mu[/tex] = 2,000 psi {means that the mean breaking strength of their climbing rope is 2,000 psi}
Alternate Hypothesis, [tex]H_A[/tex] : [tex]\mu[/tex] < 2,000 psi {means that the mean breaking strength of their climbing rope is lower than 2,000 psi}
Now, the test statistics that we will use here is One-sample z-test statistics as we know about population standard deviation;
T.S. = [tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }[/tex] ~ N(0,1)
where, [tex]\bar X[/tex] = ample mean strength = 1,997.2956 psi
[tex]\sigma[/tex] = population standard devaition = 10 psi
n = sample size
Now, at the 5% level of significance, the z table gives a critical value of -1.645 for the left-tailed test.
So, to reject our null hypothesis our test statistics must be less than -1.645 as only then we have sufficient evidence to reject our null hypothesis.
SO, T.S. < -1.645 {then reject null hypothesis}
[tex]\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } } < -1.645[/tex]
[tex]\frac{1,997.2956-2,000}{\frac{10}{\sqrt{n} } } < -1.645[/tex]
[tex](\frac{1,997.2956-2,000}{10}) \times {\sqrt{n} } } < -1.645[/tex]
[tex]-0.27044 \times \sqrt{n}< -1.645[/tex]
[tex]\sqrt{n}> \frac{-1.645}{-0.27044}[/tex]
[tex]\sqrt{n}>6.083[/tex]
n > 36.99 ≈ 37.
SO, the sample size must be greater than 37 if we want to reject the null hypothesis.
8b-ab=7a, .subtracted from 3a-9ab+b
Answer: You can't. Read explanation.
Step-by-step explanation:
You can't subtract an expression from an equation. If you said something like subtract 8b-ab+7a from 3a-9ab+b that would work, but not here.
Let's just assume You mean it as 8b-ab-7a, then (3a-9ab+b)-(8b-ab-7a) = -8ab + 10a - 7b.
Hope that helped,
-sirswagger21
Mary wants to fill in a cylinder vase. At the flower store they told her that the vase should be filled for the flowers to last the longest. Her cylinder vase has a radius of 2 in and a height of 9 in. How much water should Mary pour into the vase?
please help
Answer:
113.09 hope this helps
Step-by-step explanation:
Which of the following is true regarding the solution to the logarithmic equation below? log Subscript 2 Baseline (x + 11) = 4. x + 11 = 2 Superscript 4. x + 11 = 16. x = 5. x = 5 is not a true solution because log Subscript 5 Baseline (16) not-equals 2 x = 5 is not a true solution because log Subscript 5 Baseline (16) not-equals 4 x = 5 is a true solution because log Subscript 2 Baseline (16) = 4 x = 5 is a true solution because log Subscript 4 Baseline (16) = 2
Answer:
Option C.
Step-by-step explanation:
The given logarithmic equation is
[tex]\log_2(x+11)=4[/tex]
It can be written as
[tex](x+11)=2^4[/tex] [tex][\because log_ax=y\Leftrightarrow x=a^y][/tex]
[tex]x+11=16[/tex]
[tex]x=5[/tex]
Now, to check whether [tex]x=5[/tex] is a true solution or not. Substitute [tex]x=5[/tex] in the LHS of given equation.
[tex]LHS=\log_2(5+11)[/tex]
[tex]LHS=\log_2(16)[/tex]
[tex]LHS=\log_22^4[/tex]
[tex]LHS=4[/tex] [tex][\because log_aa^x=x][/tex]
[tex]LHS=RHS[/tex]
Hence, [tex]x=5[/tex] is a true solution because [tex]\log_2(16)=4[/tex].
Therefore, the correct option is C.
Answer:
C on edge2021
Step-by-step explanation:
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answer:
A
Step-by-step explanation:
It is not B because 7x^2 means multiplying the equation by seven. It isn't C because that would move the graph DOWN seven units. And it's not D because when it is in parenthesis like that, it means that it is a horizontal shift, not vertical.
Answer:
A. G(x) = [tex]x^2+7[/tex]
Step-by-step explanation:
→For the function to shift upwards 7 units, 7 must be added to the function, like so:
G(x) = [tex]x^2+7[/tex]
→F(x) + c (in this case is 7), cases a vertical shift and the function is moved "c," units. The graph would shift downwards if 7 was being subtracted.
This means the correct answer is A.
Which of the following statements is NOT true?
YA
The slope of AB is
different than the
slope of BC.
The ratios of the rise to
the run for the triangles
are equivalent.
B
2.
х
-2
AB has the same slope
as AC.
The slope of Ac is
Answer:
The slope of AB is
different than the
slope of BC.
Step-by-step explanation:
at a coffee shop, the first 100 customers’ orders were as follows
Answer:
81%
Step-by-step explanation:
22+5=27
22/27
Which expression is equivalent to 5^10 times 5^5. 5^2 5^5 5^15 5^50
Answer:
5^15
Step-by-step explanation:
(5^10)(5^5)= 5^10+5= 5^15
Please answer this question I give brainliest thank you! Number 9
Answer:
B
The mode is 11 and 3
The Median is 10
The mean is 12
Choose the inequality that could be used to solve the following problem.
Three times a number is at most negative six.
Answer:
3x ≤ -6
Step-by-step explanation:
"At most" means "less than or equal to." If x represents the number, then you have ...
(three) times (a number) (is at most) negative 6 . . . . . English
3 · x ≤ -6 . . . . . . . . . . . . . . . . Math
__
3x ≤ -6
Answer:
3x ≤ -6
Step-by-step explanation:
Assume that the heights of men are normally distributed with a mean of 70.9 inches and a standard deviation of 2.1 inches. If 36 men are randomly selected, find the probability that they have a mean height greater than 71.9 inches. Round to four decimal places.
Answer:
The probability that they have a mean height greater than 71.9 inches
P( x⁻ ≥71.9) = 0.0022
Step-by-step explanation:
Explanation:-
Given mean of the Population μ= 70.9
Standard deviation of the Populationσ = 2.1
Given sample size 'n' =36
let x⁻ be the mean height
given x⁻ =71.9 inches
[tex]Z=\frac{x^{-} -mean}{\frac{S.D}{\sqrt{n} } }[/tex]
[tex]Z=\frac{71.9 -70.9}{\frac{2.1}{\sqrt{36} } } = \frac{1}{0.35} = 2.85[/tex]
The probability that they have a mean height greater than 71.9 inches
P( x⁻ ≥71.9) = P(Z ≥ 2.85)
= 1 - P(Z≤ 2.85)
= 1 - ( 0.5 + A(2.85)
= 0.5 - A( 2.85)
= 0.5 - 0.4978
= 0.0022
The probability that they have a mean height greater than 71.9 inches
P( x⁻ ≥71.9) = 0.0022
Answer:
the answer is 0.0022
Step-by-step explanation:
13. Carla drew two acute non-overlapping
angles that share a ray and labeled them
ZJLK and Z KLM. The two angles have
different measures. Carla says
ZILM is
greater than a right angle.
An acute angle is open
less than a right angle.
Answer:
An acute angle is open
Step-by-step explanation:
An acute angle is an angle that is less than [tex]90^{0}[/tex]. Two or more acute angles are set to be complementary if their sum equals a right angle.
Clara's diagram involves two acute angles JLK and KLM with both sharing the side LK.
If the acute angles are complementary angles, then JLM would be a right angle.
If the acute angles are not complementary angles, then JLM would be less than a right angle.
So the appropriate choice to select is an acute angle is open. Which implies that JLM may be a right angle or not depending on the degrees of the acute angles involved.
Suppose 90 geology students measure the mass of an ore sample. Due to human error and limitations in the reliability of the​ balance, not all the readings are equal. The results are found to closely approximate a normal​ curve, with mean 88 g and standard deviation 1 g. Use the symmetry of the normal curve and the empirical rule as needed to estimate the number of students reporting readings between 87 g and 89 g.The number of students reporting readings between 87 g and 89 g is:________
Answer:
The number of students reporting readings between 87 g and 89 g is 61
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 88g
Standard deviation = 1g
Percentage of students reporting readings between 87 g and 89 g
87 = 88-1
So 87 is one standard deviation below the mean.
89 = 88+1
So 89 is one standard deviation above the mean.
By the Empirical Rule, 68% of students are reporting readings between 87 g and 89 g.
Out of 90 students:
0.68*90 = 61.2
Rounding to the nearest whole number:
The number of students reporting readings between 87 g and 89 g is 61
Aisha needs to be at least 48 inches tall to ride the colossal coaster at the amusement park. If she grows 5 inches during the next year, Aisha will still not be tall enough to ride. In the context of this situation, what does the inequality x less-than 43 represent?
Answer:
Aisha is shorter than 43 inches.
Step-by-step explanation:
[tex]x+5=48[/tex]
[tex]x=48-5[/tex]
[tex]x=43[/tex]
[tex]x >43[/tex]
Answer:
The answer is B!
Step-by-step explanation:
Test taking! <3
A student's tuition was $1200. A loan was obtained for 5/6 of the tuition. How much was the loan?
Answer:
the loan was 1000
Step-by-step explanation:
Take the tuition and multiply by 5/6
1200 *5/6
1200/6 *5
200 *5
1000
Answer:
$1000
Step-by-step explanation:
In order to find 5/6 of the tuition, we just need to multiply the 2 values together.
5/6*1200
Note that 1200 = 1200/1
5/6*1200/1
When multiplying fractions, we can multiply the numerators together, and the denominators together.
5*1200/6*1
6000/6
Divide.
1000
Therefore, the loan was $1000.
According to the U.S. Census Bureau, the mean of the commute time to work for a resident of Boston, Massachusetts, is 27.3 minutes with a standard deviation of 8.1 minutes. What minimum percentage of commuters in Boston has a commute time within 2 standard deviations of the mean
Answer:
By the Chebyshev Theorem, at least 75% of commuters in Boston has a commute time within 2 standard deviations of the mean
Step-by-step explanation:
Chebyshev Theorem
The Chebyshev Theorem can also be applied to non-normal distribution. It states that:
At least 75% of the measures are within 2 standard deviations of the mean.
At least 89% of the measures are within 3 standard deviations of the mean.
An in general terms, the percentage of measures within k standard deviations of the mean is given by [tex]100(1 - \frac{1}{k^{2}})[/tex].
What minimum percentage of commuters in Boston has a commute time within 2 standard deviations of the mean
By the Chebyshev Theorem, at least 75% of commuters in Boston has a commute time within 2 standard deviations of the mean
95% of commuters in Boston has a commute time within 2 standard deviations of the mean
Empirical ruleEmpirical rule states that for a normal distribution, 68% of the values are within one standard deviation from the mean, 95% of the values are within two standard deviation from the mean and 99.7% of the values are within three standard deviation from the mean.
Hence, 95% of commuters in Boston has a commute time within 2 standard deviations of the mean
Find out more on Empirical rule at: https://brainly.com/question/10093236
Please show me how to solve 40% of X is 23?
NOT what is 40% of 23. But what number is 40% of to equal 23.
Thank you!!
Answer: The answers are in the steps hopes it helps.
Step-by-step explanation:
40% * x = 23 convert 40% to a decimal
0.4 * x = 23 multiply 0.4 is by x
0.4x = 23 divide both sides by 0.4
x= 57.5
Check:
57.5 * 40% = ?
57.5 * 0.4 = 23
I don’t know if it’s g(2(5)(3(5)^2-5-5
Answer:
B. 135
Step-by-step explanation:
For ...
f(x) = 3x^2 -xg(x) = 2x -5f(5) = 3·5^2 -5
= 3·25 -5 = 75 -5 = 70
Then g(f(5)) is ...
g(f(5)) = g(70) = 2·70 -5 = 140 -5
g(f(5)) = 135 . . . . . matches choice B
The value z is directly proportional to c. When z = 20, c = 10. Find an equation relating z and c. *
Answer:
a) The equation of Z and C is Z =K C
b) K = 2
Step-by-step explanation:
Explanation :-
Given data Z is directly proportional to C
⇒ Z ∝ C
⇒ Z = K C
The equation of relating Z and C
Z = K C
Given Z = 20 and C =10
20 = K ( 10)
⇒ K = 2
