Answer:
When variables are the same, multiplying them together compresses them into a single factor (variable). ... When multiplying variables, you multiply the coefficients and variables as usual. If the bases are the same, you can multiply the bases by merely adding their exponents.
Step-by-step explanation:
The point A(−8,−4) is reflected over the origin and its image is point B. What are the coordinates of point b?
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Answer:
B(8, 4)
Step-by-step explanation:
Reflection across the origin negates both coordinate values.
(x, y) ⇒ (-x, -y) . . . . . reflection across the origin
A(-8, -4) ⇒ B(8, 4)
The 100 members of an extracurricular club at a nearby college are subdivided into 6
groups based on ethnic identification. Since 40% of the club is Caucasian, the
researcher ensures that 40% of his sample is also Caucasian. The researcher is using_____sampling
sampling.
A.random
B.cluster
C.stratified
D.systematic
Explanation:
Stratified sampling involves breaking a population of people into separate groups, where there isn't any overlap.
An example would be having a high school with freshmen, sophomores, juniors and seniors. A person can only belong to one group (so we can't have someone whos a freshman and a sophomore at the same time for instance). In that example, each group or strata is a different grade level.
As for this particular problem, each strata is a different ethnicity, and there are 6 strata total.
The researcher is using stratified sampling. The correct option is C.
What is stratified sampling?A method of sampling from a population that can be divided into subpopulations is known as stratified sampling in statistics. When subpopulations within a larger population differ, it may be desirable to sample each subpopulation separately in statistical surveys.
Stratified sampling involves breaking a population of people into separate groups, where there isn't any overlap.
An example would be having a high school with freshmen, sophomores, juniors, and seniors. A person can only belong to one group (so we can't have someone whos a freshman and a sophomore at the same time for instance). In that example, each group or strata is a different grade level.
As for this particular problem, each stratum is different ethnicity, and there is 6 strata total.
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- Mean test score was 200 with a standard deviation of 40- Mean number of years of service was 20 years with a standard deviation of 2 years.In comparing the relative dispersion of the two distributions, what are the coefficients of variation
Answer:
The correct answer is "Test 20%, Service 10%".
Step-by-step explanation:
As we know,
The coefficient of variation (CV) is:
⇒ [tex]CV=\frac{Standard \ deviation}{Mean}\times 100[/tex]
Now,
CV of test will be:
= [tex]\frac{40}{200}\times 100[/tex]
= [tex]20[/tex] (%)
CV of service will be:
= [tex]\frac{2}{20}\times 100[/tex]
= [tex]10[/tex] (%)
How many solutions does the nonlinear system of equations graphed below have?
A. Four
B. Two
C. One
D. Zero
Answer:
Option (A)
Step-by-step explanation:
Solution of two functions represented by the graph are the common points or point of intersection of the graphs.
From the graph attached,
Parabola and ellipse are intersecting each other at four points.
Therefore, solutions of the given non linear functions will be FOUR.
Option (A) will be the correct option.
Base conversion. Perform the following conversion
675_10= ?___6
Answer:
3043 (base 6)
Step-by-step explanation:
216 36 6 1
3 0 4 3
216* 3 = 648
6*4 = 24
1*3 = 3
648+24+3 = 675
The graph of the function f(x) = (x + 2)(x + 6) is shown below.
On a coordinate plane, a parabola opens up. It goes through (negative 6, 0), has a vertex at (negative 4, negative 4), and goes through (negative 2, 0).
Which statement about the function is true?
The function is positive for all real values of x where
x > –4.
The function is negative for all real values of x where
–6 < x < –2.
The function is positive for all real values of x where
x < –6 or x > –3.
The function is negative for all real values of x where
x < –2.
Answer:
2nd option,
The function is negative for all read values of x where -6<x<-2
The function f(x) = (x + 2)(x + 6) is a quadratic function, and the function is negative for all real values of x where –6 < x < –2.
What are quadratic functions?Quadratic functions are functions that have an exponent or degree of 2
The function is given as:
f(x) = (x + 2)(x + 6)
From the graph of the function, the vertex is at (-4,-4) and the x-intercepts are at x = -6 and x = -2
Since the vertex is minimum, then the function is negative for all real values of x where –6 < x < –2.
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Sodium chlorate crystals are easy to grow in the shape of cubes by allowing a solution of water and sodium chlorate to evaporate slowly. If V is the volume of such a cube with side length x, calculate the derivative when x = 5 mm.
V'(5) = mm3/mm
What does V'(5) mean in this situation?
Answer:
I don't know the answer it is to hard.
Use the elimination method to solve this system. − 4 x − 2 y = − 12, 4 x + 8 y = − 24
Answer:
x = 6; y = -6
Step-by-step explanation:
-4x - 2y = -12
4x + 8y = -24
Add the two equations, so x is eliminated:
6y = -36
6y/6 = -36/6
y = -6
Plug in y, to solve for x
-4x - 2y = -12
-4x - 2(-6) = -12
-4x +12 = -12
-4x = -12 -12
-4x = -24
-4x/-4 = -24/-4
x = 6
Answer from Gauthmath
could someone please answer this? :) thank you
Answer:
The last one
Step-by-step explanation:
What we know:
We have a total of 16 coins
The 16 coins consist of dimes and quarters
The value of the coins is 3.10
The value of a dime is .10
The value of a quarter is .25
Using this information we can create a system of linear equations
First off we know that we have a total of 16 coins which consist of dimes and quarters
The number of Quarters can be represented by q and then number of dimes can be represented by d.
If we have a total of 16 coins then q + d must equal 16
So equation 1 is q + d = 16
Now we need to create a second equation
We know that the total value of the coins is 3.10 and we know that the coins consist of dimes and quarters
As you may know a quarter has a value of .25 cents and a dime has a value of 10 cents
If the total value of the coins is 3.10 the the number of dimes (d) times .10 + the number of Quarters times .25 must equal 3.10
This can also be written as
.25q + .10d = 3.10
So the two equations are
q + d = 16 and .25q + .10d = 3.10
These equations are shown in the last answer choice
Note: b is very similar to d
However the the value of the coins are incorrect in B
In B the value of the dime is represented by 10 which is not correct because the value of a dime is .10 not 10
A telephone call arrived at a switchboard at random within a one-minute interval. The switch board was fully busy for 10 seconds into this one-minute period. What is the probability that the call arrived when the switchboard was not fully busy
Answer:
50/60 = .8333= 83.33%
Step-by-step explanation:
The probability that the call arrived when the switchboard was not fully busy is 0.75.
What is Normal Distribution?A probability distribution that is symmetric about the mean is the normal distribution, sometimes referred to as the Gaussian distribution. It demonstrates that data that are close to the mean occur more frequently than data that are far from the mean. The normal distribution appears as a "bell curve" on a graph.
Given:
Here X follows uniform distribution with parameter a and b.
Where,
a = 0 and b = 1.
Then,
The density function of Y is given by:
P( 15 < Y ≤ 60)
or, P( 0.25 < Y ≤ 1)
So, P( 0.25 < Y ≤ 1) = [tex]\int\limits^{1}_{0.25}{f(y) \, dy[/tex]
= [tex][y]^1 _ {0.25}[/tex]
= (1- 0.25)
= 0.75
Hence, The probability that the call arrived when the switchboard was not fully busy is 0.75.
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A bag contains 35 marbles, 11 of which are red. A marble is randomly selected from the bag, and it is blue. This blue marble is NOT placed back in the bag. A second marble is randomly drawn from the bag. Find the probability that this second marble is NOT red.
Answer:
11 red + 24 blue = 35 marbles
If 1 blue is withdrawn
11 red + 23 blue = 34 marbles
P = 23 / 34 = .38 probability of drawing blue marble
Helen’s father’s car can travel an average of 18.5 miles on 1 gallon of gasoline. Gas at the local station costs $3.79 per gallon.
a) Helen’s mom took the car to the gas station and hand the cashier a $10 bill. How much gas could she buy? Round your answer to the nearest hundredth of a gallon.
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Answer:
2.64 gallons
Step-by-step explanation:
Each gallon costs $3.79, so the number of gallons that can be bought with $10 is ...
$10/($3.79/gal) = (10/3.79) gal ≈ 2.6385 gal ≈ 2.64 gallons
Find the equation of the line passing through the point (1, -5)
and perpendicular to y 1x + 2
Answer:
-8 and 3
Step-by-step explanation:
The slope of the line will be - 8, the equation is y=-8x+3
Find the missing length. The triangles are similar.
Answer:
Missing length = 12
Step-by-step explanation:
Let x represent the missing length.
Since the triangles are similar, ∆KLM ~ ∆KRS, therefore, the ratio of their corresponding side lengths would be the same. This implies that:
KL/KR = KM/KS
KL = 65
KR = 65 - 52
KR = 13
KM = 60
KS = x
Plug in the values
65/13 = 60/x
Cross multiply
65*x = 60*13
65x = 780
Divide both sides by 65
65x/65 = 780/65
x = 12
Rationalize the denominator in the expression.
[tex] \frac{4}{\sqrt{2} } [/tex]
Answer:
2[tex]\sqrt{2}[/tex]
Step-by-step explanation:
See the photo for the steps. :)
Write the number 16,107,320 expanded form.
Answer:
Sixteen million, one hundred and seven thousand, three hundred twenty
Step-by-step explanation:
Which three relations are functions? Select all correct answers
Answer:
the 3rd, 4th, and 5th one
Step-by-step explanation:
Answer:
Step-by-step explanation:
:)
The height of the triangle is 4 meters longer than twice its base. find the height if the area of the triangle is 80 square meters. The height must be ___meters
Answer:
The height is 20 meters
Step-by-step explanation:
First set up the equation (Area)80=bh/2 then set up another equation, (height) h=4+2b (base). After this you can substitute h in the equation to end up with 80=(b(2b+4))/2 simplify it to get 80=b^2+2b then solve. The base is 8 meters, plug into the formula that we made before and you find the height is 20 meters.
Hey guys can help me please
Answer:
Can you select multiple answers to this question? then option A, B and C all three applies, if only one the go for option C, since that's the major change happens to the parent function
In ΔABC, if AB = 10 and BC = 6, AC can NOT be equal to
Answer:
Step-by-step explanation:
4
A. Use the appropriate formula to determine the periodic deposit.
B. How much of the financial goal comes from deposits and how much comes from interest?
Periodic Deposit: $? at the end of each year
Rate: 7% compounded annually
Time: 18 years
Financial Goal: $130,000
The periodic deposit is? $
Answer:
A. Periodic deposit:
The goal is to make $130,000 by depositing a set amount every year.
This set amount is an annuity. The $130,000 is therefore the future value of the annuity after 18 years.
Future value of annuity = Annuity * Future value of annuity factor, 7%, 18 years
130,000 = Annuity * 33.9990
Annuity = 130,000 / 33.9990
= $3,823.64
B. Sources of the financial goal.
Money from deposits = Periodic deposit * no. of years
= 3,823.64 * 18
= $68,825.52
Money from interest:
= Financial goal - Money from deposits
= 130,000 - 68,825.52
= $61,174.48
Help with This question please
Answer:
A
Step-by-step explanation:
Carlos owns a small business. There was a profit of $9 on Saturday and a loss of $6 on Sunday. Find the total profit or loss for the weekend. $15 profit $3 loss $3 profit $15 loss
Answer:
$3 profit
Step-by-step explanation:
Since you got a profit of $9 on Saturday and a loss of $6 on Sunday, you have to subtract 9 and 6, which is 3.
at a local college, four sections of economics are taught during the day and two sections are taught at night. 85 percent of the day sections are taught by full-time faculty. 30 percent of the evening sections are taught by full-time faculty. if jane has a part-time teacher for her economics course, what is the probability that she is taking a night class
Answer:
Hence The probability that she is taking a night class given that Jane has a part-time teacher = P(jane has a part-time teacher and she is taking night class )/P(jane has a part-time teacher) = 0.6999.
Step-by-step explanation:
Probability(full-time teacher/ day ) = 0.85
Probability(part-time teacher/ day ) = 1- 0.85 = 0.15
Probability(full-time teacher/ night) = 0.30
Probability(part-time teacher/ night) = 1 - 0.30 = 0.70
total no of section = 4+2 = 6
P(jane has part time teacher) = P(jane is from day section)*Probability(part-time teacher/ day )+P(jane is from night section)*Probability(part-time teacher/ night)
= (4/6)(0.15)+(2/6)(0.70) = 0.33
P(jane has part time teacher and she is taking night class ) = P(jane is from night section)*Probability(part-time teacher/ night) = (2/6)(0.70) = 0.23
According to Bayes theorem :
The probability that she is taking a night class given that Jane has a part-time teacher = P(jane has a part-time teacher and she is taking night class )/P(jane has a part-time teacher)
= 0.23/0.33
= 0.6999
Which best describes the relationship between the lines with equations 2x – 9y = 1 and x + 8y = 6?
A. perpendicular
B. neither perpendicular nor parallel
C. parallel
D. same line
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Answer:
B. neither perpendicular nor parallel
Step-by-step explanation:
If the lines were perpendicular, the coefficients would be swapped and one negated. (You would have 8x -y = c, or 9x +2y = c in the system.)
If the lines were parallel, the coefficients in the two equations would only differ by a common factor. (Both equations would reduce to 2x -9y = c, or x +8y = c.)
The lines are not the same line (coefficients are different).
So, the only reasonable description is ...
neither perpendicular nor parallel
People were asked if they owned an artificial Christmas tree. Of 78 people who lived in an apartment, 38 own an artificial Christmas tree. Also it was learned that of 84 people who own their home, 46 own an artificial Christmas tree. Is there a significant difference in the proportion of apartment dwellers and home owners who own artificial Christmas trees
Answer:
The p-value of the test is 0.4414, higher than the standard significance level of 0.05, which means that there is not a a significant difference in the proportion of apartment dwellers and home owners who own artificial Christmas trees.
Step-by-step explanation:
Before testing the hypothesis, we need to understand the central limit theorem and subtraction of normal variables.
Central Limit Theorem
The Central Limit Theorem establishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]
Subtraction between normal variables:
When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.
Apartment:
38 out of 78, so:
[tex]p_A = \frac{38}{78} = 0.4872[/tex]
[tex]s_A = \sqrt{\frac{0.4872*0.5128}{78}} = 0.0566[/tex]
Home:
46 out of 84, so:
[tex]p_H = \frac{46}{84} = 0.5476[/tex]
[tex]s_H = \sqrt{\frac{0.5476*0.4524}{84}} = 0.0543[/tex]
Test if the there a significant difference in the proportion of apartment dwellers and home owners who own artificial Christmas trees:
At the null hypothesis, we test if there is no difference, that is, the subtraction of the proportions is equal to 0, so:
[tex]H_0: p_A - p_H = 0[/tex]
At the alternative hypothesis, we test if there is a difference, that is, the subtraction of the proportions is different of 0, so:
[tex]H_1: p_A - p_H \neq 0[/tex]
The test statistic is:
[tex]z = \frac{X - \mu}{s}[/tex]
In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis, and s is the standard error.
0 is tested at the null hypothesis:
This means that [tex]\mu = 0[/tex]
From the samples:
[tex]X = p_A - p_H = 0.4872 - 0.5476 = -0.0604[/tex]
[tex]s = \sqrt{s_A^2 + s_H^2} = \sqrt{0.0566^2 + 0.0543^2} = 0.0784[/tex]
Value of the test statistic:
[tex]z = \frac{X - \mu}{s}[/tex]
[tex]z = \frac{-0.0604 - 0}{0.0784}[/tex]
[tex]z = -0.77[/tex]
P-value of the test and decision:
The p-value of the test is the probability of the difference being of at least 0.0604, to either side, plus or minus, which is P(|z| > 0.77), given by 2 multiplied by the p-value of z = -0.77.
Looking at the z-table, z = -0.77 has a p-value of 0.2207.
2*0.2207 = 0.4414
The p-value of the test is 0.4414, higher than the standard significance level of 0.05, which means that there is not a a significant difference in the proportion of apartment dwellers and home owners who own artificial Christmas trees.
Three different classes contain 20, 18, and 25 students, respectively, and no student is a member of more than one class. If a team is to be composed of one student from each of these three classes, in how many different ways can the members of the team be chosen?
Answer:
9000
Step-by-step explanation:
20 x 18 x 25
20 options for one member
18 options for another member
25 members for the last member
Fixed costs are $2000, and the cost of producing each pair of skies is $100. The selling price is $220 (per pair). How many pairs should be sold to make a profit of $29200?
260 pairs
Step-by-step explanation:
220-100= 120
(29200+2000)÷120= 260
sin4x.sin5x+sin4x.sin3x-sin2x.sinx=0
Recall the angle sum identity for cosine:
cos(x + y) = cos(x) cos(y) - sin(x) sin(y)
cos(x - y) = cos(x) cos(y) + sin(x) sin(y)
==> sin(x) sin(y) = 1/2 (cos(x - y) - cos(x + y))
Then rewrite the equation as
sin(4x) sin(5x) + sin(4x) sin(3x) - sin(2x) sin(x) = 0
1/2 (cos(-x) - cos(9x)) + 1/2 (cos(x) - cos(7x)) - 1/2 (cos(x) - cos(3x)) = 0
1/2 (cos(9x) - cos(x)) + 1/2 (cos(7x) - cos(3x)) = 0
sin(5x) sin(-4x) + sin(5x) sin(-2x) = 0
-sin(5x) (sin(4x) + sin(2x)) = 0
sin(5x) (sin(4x) + sin(2x)) = 0
Recall the double angle identity for sine:
sin(2x) = 2 sin(x) cos(x)
Rewrite the equation again as
sin(5x) (2 sin(2x) cos(2x) + sin(2x)) = 0
sin(5x) sin(2x) (2 cos(2x) + 1) = 0
sin(5x) = 0 or sin(2x) = 0 or 2 cos(2x) + 1 = 0
sin(5x) = 0 or sin(2x) = 0 or cos(2x) = -1/2
sin(5x) = 0 ==> 5x = arcsin(0) + 2nπ or 5x = arcsin(0) + π + 2nπ
… … … … … ==> 5x = 2nπ or 5x = (2n + 1)π
… … … … … ==> x = 2nπ/5 or x = (2n + 1)π/5
sin(2x) = 0 ==> 2x = arcsin(0) + 2nπ or 2x = arcsin(0) + π + 2nπ
… … … … … ==> 2x = 2nπ or 2x = (2n + 1)π
… … … … … ==> x = nπ or x = (2n + 1)π/2
cos(2x) = -1/2 ==> 2x = arccos(-1/2) + 2nπ or 2x = -arccos(-1/2) + 2nπ
… … … … … … ==> 2x = 2π/3 + 2nπ or 2x = -2π/3 + 2nπ
… … … … … … ==> x = π/3 + nπ or x = -π/3 + nπ
(where n is any integer)
4.Siti and Janice spent 3h 25min altogether in Shopping malls A and B. If they spent 1h 45min in Shopping mall A, how long did they spend in Shopping mall B?
Answer:
1 hour and 40 minutes
Step-by-step explanation:
→ Convert 3 hr and 25 minutes to minutes
( 3 × 60 ) + 25 = 205 minutes
→ Convert 1 hr and 45 minutes to minutes
( 1 × 60 ) + 45 = 105 minutes
→ Minus the answers from each other
205 - 105 = 100 minutes
→ Convert 100 minutes to hours and minutes
1 hour and 40 minutes
