Answer: random sampling
Step-by-step explanation:
Because psychologists generally use college students as research participants, the research does not involve random sampling.
Random sampling is when each sample has an equal chance of being selected. Since the psychologists are targeting a particular set of students, the random sampling might not be applicable in this case.
Someone help me with these math problems please !! (It is not obligatory to put the explanation so I save time and you will answer me more quickly please!
Answer:
I don't know the selection options, so please pick them from the explanation below.
Step-by-step explanation:
"like terms" are in this contexts in one group all expressions with x, and in another group all expressions without x.
so,
3x and -2x/9
3x - 2x/9 = 27x/9 - 2x/9 = 25x/9
-1/5 ... = 124/5
... = 125/5 = 25
so, we end up with
25x/9 = 25
x/9 = 1
x = 9
There are 28 marbles in the box. There are 12 red marbles, 10 blue marbles, and 6 yellow marbles. What percent of the marbles are NOT yellow?
Answer:
There are 28 marbles in the box. Some are red (12), others are yellow (6) and others are blue (10).
If in this box there 28 marbles and 6 of them are yellow, we substract to get the quantity of marbles that aren't yellow: 28-6 = 22
So 22 of the 28 marbles aren't yellow: 22/28, which we can simplify dividing the numerator and denominator by 2: 11/14
Write a recursive rule for the sequence.
x, x, 2x, 3x, 5x, 8x, ...
I know that it adds its last term but I don't know the rule/formula to show that.
Answer:
f(n)=f(n-1)+f(n-2)
f(1)=1x
f(2)=1x
Step-by-step explanation:
This is the fibonacci sequence with each term times x.
Notice, you are adding the previous two terms to get the third term per consecutive triples of the sequence.
That is:
1x+1x=2x
1x+2x=3x
2x+3x=5x
3x+5x=8x
So since we need the two terms before the third per each consecutive triple in the sequence, our recursive definition must include two terms of the sequence. People normally go with the first two.
f(1)=1x since first term of f is 1x
f(2)=1x since second term of f is 1x
Yes, I'm naming the sequence f.
So I said a third term in a consecutive triple of the sequence is equal to the sum of it's two prior terms. Example, f(3)=f(2)+f(1) and f(4)=f(3)+f(2) and so on...
Note, the term before the nth term is the (n-1)th term and the term before the (n-1)th term is the (n-2)th term. Just like before the 15th term you have the (15-1)th term and before that one you have the (15-2)th term. That example simplified means before the 15th term you have the 14th and then the 13th.
So in general f(n)=f(n-1)+f(n-2).
So the full recursive definition is:
f(n)=f(n-1)+f(n-2)
f(1)=1x
f(2)=1x
write missing monomial to make an identity ( + 2a)^2 = + 12ab + 4
Answer:
The missing monomial should be [tex]3b[/tex].
Step-by-step explanation:
Given that,
[tex]( + 2a)^2 = + 12ab + 4[/tex]
Let the missing monomial is x.
[tex]( x+ 2a)^2 = x^2+ 12ab + 4a^2\\\\( x+ 2a)^2=(3b)^2+ 2(2a)(3b) + (2a)^2\\\\So,\\\\( 3b+ 2a)^2=(3b)^2+ 2(2a)(3b) + (2a)^2[/tex]
So, the missing monomial should be [tex]3b[/tex].
As x increases by 1 unit, what is the exponential growth factor??
Given:
The graph of an exponential function.
To find:
The exponential growth factor as x increases by 1 unit.
Solution:
From the given graph, it is clear that the exponential function passes through the points (1,1) and (3,9). So, the equation of the exponential must must be satisfy by these points.
The general exponential function is:
[tex]y=ab^x[/tex] ...(i)
Where, a is the initial value and b is the growth factor.
Putting [tex]x=1,y=1[/tex] in (i), we get
[tex]1=ab^1[/tex] ...(ii)
Putting [tex]x=3,y=9[/tex] in (i), we get
[tex]9=ab^3[/tex] ...(iii)
Divide (iii) by (ii).
[tex]\dfrac{9}{1}=\dfrac{ab^3}{ab}[/tex]
[tex]9=b^2[/tex]
[tex]3=b[/tex]
b is the the growth factor and the value of b is 3.
Therefore, the exponential growth factor is 3 as x increases by 1 unit.
Answer:
exponential growth factor is 3
Step-by-step explanation:
Help 10 points please
Answer:
R
The radius is the height from the bottom to the top.
A population that is neither growing nor declining will have a TFR of ________. A population that is neither growing nor declining will have a TFR of ________. 2.1 1.2 less than 1.0 zero greater than 2.1
A population that is neither growing nor declining will have a TFR (Total Fertility Rate) of 2.1.
A population that is neither growing nor declining will have a Total Fertility Rate (TFR) of 2.1. The TFR is the average number of children that a woman of reproductive age will have in her lifetime.
A TFR of 2.1 is considered to be the replacement level for a population, meaning that the population will remain stable over time as births are balanced by deaths.
A TFR less than 1.0 would indicate a population in decline, while a TFR greater than 2.1 would indicate a population in growth.
Therefore, a population that is neither growing nor declining will have a TFR (Total Fertility Rate) of 2.1.
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PLEASE GIVE AN ANSWER AND EXPLANATION! I BEG YOU. I REALLY NEED SOMEBODY TO ANSWER!!!
Answer:
27y^12
Step-by-step explanation:
you multiply the exponents together
in this case: 4×3=12
and then multiply the base number by 3 as well.
answer please i need to pass this class
Answer:
b
Step-by-step explanation:
Answer: B (option 3)
Step-by-step explanation:
When you multiply [tex]\sqrt{b}[/tex] by itself, the two square roots cancel our, giving you just b.
I will mark brainliest!!
The equation for the circle below is x2 + y2 = 100. What is the length of the
circle's radius?
Answer:
Step-by-step explanation:
x²+y² =(Radius)²
x²+y² =10². So the radius is 10
Answer:
radius = 10
Step-by-step explanation:
The equation of a circle centred at the origin is
x² + y² = r² ( where r is the radius )
x² + y² = 100 ← is in this form
with r² = 100 ( take the square root of both sides )
r = [tex]\sqrt{100}[/tex] = 10
PLEASE HELP !!!
Annabelle went to the store to buy some apples. The price per pound of the apples is $3.75 per pound and she has a coupon for $3.25 off the final amount. With the coupon, how much would Annabelle have to pay to buy 3 pounds of apples? Also, write an expression for the cost to buy pp pounds of apples, assuming at least one pound is purchased.
final cost of 3 pounds: ______
final cost of p pounds: ______
Answer:
final cost of 3 pounds: 8 dollars
final cost of p pounds: 3.75p - 3.25 dollars
Step-by-step explanation:
Each pound costs $3.75, so 3 pounds cost 3*3.75 = 11.25 dollars. Subtract off the $3.25 to get the final cost to be 11.25-3.25 = 8 dollars. This takes care of the first part.
For the second part, the expression for the final cost is 3.75p - 3.25; where the 3.75p is the cost before the coupon is applied. If you plugged p = 3 into that expression, you should get 8 as a result. The variable p is some positive whole number. It's a place holder for the number of pounds of apples.
3c(p-6)+4(p-6)= write the correct expression in factored form.
[tex]\tt\displaystyle\ 3c\underline{(p-6)}+4\underline{(p-6)}=(p-6)(3c+4)[/tex]
A post office charges 50k for a telegram of 15 words or less it charges an extra 3k for every word above 15 words find the cost of 30 words
Answer:
95k
Step-by-step explanation:
Given :
15 words or less = 50k
Every word above 15 = additional 3k
The cost of 30 words :
First 15 words = 50 k
Number of additional words = (30 - 15) = 15 words
Cost of every additional word = 3 k
Cost of 15 additional word = 15 * 3 = 45k
Total cost of 30 words :
50k + 45k = 95k
Figure A is a scale image of Figure B. What is the value of x?
khan academy
Answer:
maybe 12 because
Step-by-step explanation:
30/25=1.2
10×1.2=12
Would appreciate I’m so far behind :/
Answer:
C
Step-by-step explanation:
Given the graph of f(x) then the graph of f(x + a) is a horizontal translation of f(x)
• If a > 0 then a shift to the left of a units
• If a < 0 then a shift to the right of a units
Here the graph has been shifted 2 units to the right , then
f(x) = (x - 2)²
Given the graph of f(x) then f(x) + c is a vertical translation of f(x)
• If c > 0 then a shift up of c units
• If c < 0 then a shift down of c units
Here the graph has ben shifted 4 units up
Thus
f(x) = (x - 2)² + 4 → C
help can you please help question a b and c
(with the working out)
Answer:
a) 12 'o' clock, b) 30 minutes c) you can do it your answer may differ
Step-by-step explanation:
a) look closely you will see it is 24 hours format, so it is proved she starts going to town at that that time
b) look you there is a downward movement of graph means it shows she is not travelling she is resting done let after 1500 or 3:00pm and before 1600 or 4:00pm point be 3:30 so till 3:30 to 4:00 rested in town
c) answer may differ
pls thank me and mark brainliest if you can
PLEASE HELP!!! WILL GIVE BRAINLIEST!!!
Answer:
Step-by-step explanation:
Marco is incorrect because a function is a relation for which each input has a different output. An example of a function is y=2x each input x has a different output y.
Numbers are formed using the digits 1, 2, 3, 4, 5, 6. If no digit may be repeated, how many two-digit
numbers can be formed
A. 15
B. 20
C. 30
D. 6
I got 20.
I may have done it wrong so maybe wait until others have answered.
A company is selling specialty ice cream. Their profit is modeled by the equation p(x) = x2 + 3, where x represents the number of cartons sold. Their cost to make the carton is represented by c(x) = -3x + 24, where x represents the number of cartons produced.
A. What does it mean to find the solution to this system?
B. What is the solution to the system? How did you find the solution?
C. What does the solution mean in context of the problem?
D. How do you solve this system when x does not stand for the same thing? What system are you referring to?
Answer:
The given function for the profit of the company is p(x) = x² + 3
The function for the cos of the company, c(x) = -3·x + 24
Where;
x = The number of cartons sold
A. To find the solution of the system means to find the number of cartons sold at which the profit and cost are equal
B. The solution of the system can be found by equating both functions as follows;
p(x) = c(x)
Therefore;
x² + 3 = -3·x + 24
∴ x² + 3 + 3·x - 24 = 0
x² + 3·x - 21 = 0
x = (-3 ± √(3² - 4×1×(-21)))/(2 × 1)
∴ x = (-3 ± √(93))/2
x = (-3 + √(93))/2 ≈ 3.32 or x = (-3 - √(93))/2 ≈ -6.32
Therefore, the possible solution is x = (-3 + √(93))/2 ≈ 3.32
C. The solution means that when the company sells about 3 cartons of specialty ice, the cost to make the carton and the profit from selling the cartons will be approximately equal
D. Part 1
To solve the system, we rewrite the functions using common variables, to obtain a consistent system of equations
Part 2 Inconsistent system of equations
When x does not stand for the same thing in both equations, we have an inconsistent system of equations and there are no solutions
Step-by-step explanation:
3y+30=6x
What is the solution to the system?
Answer:
6x+y=30
-9x+3y=-18
Solving by substitution means that you have to express one of the variables (from one the equations) through the other one and substitute in the second equation.
In this example it is easier to express y through x in the first equation: y=30-6x. Put the expression for y in the second equation and solve for x.
-9x+3(30-6x)=-18 (divide by -3)
3x-30+6x=6
9x=36
x=4,
y=30-6x=30-24=6
Step-by-step explanation:
sin^2x + sin2x +2cox^2x = 2
Answer:
Step-by-step explanation:
[tex]sin^2 \ x + sin ^2 \ x + 2cos^ 2\ x = 2\\\\2sin^2 \ x + 2 cos^2 \ x = 2\\\\2 ( sin^2 \ x + cos^2 \ x ) = 2 \\\\2 \times 1 = 2 \\\\2 = 2 \\\\LHS = RHS \\\\Hence \ proved.[/tex]
Susanna deposits $400 in a savings account with an interest rate of 3% compounded annually. What equation could Susanna use to calculate how many years it will take for the value of the account to reach $600?
Fill in the values of A, b, and c to write the equation modeling this situation.
Answer:
So, you have $400savings, 3%intrest rate, you'll need to have $400 and a 10%intrest rate.
I hope this helps
Step-by-step explanation:
How many solutions are there to the equation below? 9(x – 4) = 9x – 33
Answer:
There are 0 solutions
Step-by-step explanation:
9(×-4)=9×-33
9×-36=9×-33
9×-9×-36=-33
-36=-33 and it's impossible
so there's 0 solutions
An operator in the plant receives a monthly salary. His rent, which is $849, takes up exactly 1/3 13 of his pay. What is his total pay per month?
Answer:
Below.
Step-by-step explanation:
(1/3)X = 849
x = 849*3 = 2547
The total pay per month of an operator is equal to $2547.
What is an expression?The mathematical expression combines numerical variables and operations denoted by addition, subtraction, multiplication, and division signs.
Mathematical symbols can be used to represent numbers (constants), variables, operations, functions, brackets, punctuation, and grouping. They can also denote the logical syntax's operation order and other properties.
Given that an operator in the plant receives a monthly salary. His rent, which is $849, takes up exactly 1/3.
The total monthly salary will be calculated as,
(1/3)X = 849
X = 849 x 3
X= 2547
Therefore, the total pay per month of an operator is equal to $2547.
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Drag each condition to the correct location on the table.
Match each condition to the number of triangles that can be constructed to fit the condition.
condition A: one side
measuring 4 inches,
another side measuring
8 inches, and a third
side measuring 10 inches
condition B: one angle
measuring 60°, another
angle measuring 40°, and
a third angle measuring 90°
condition C: one side
measuring 4 inches,
another side measuring
8 inches, and the angle
between them measuring 70°
condition D: one side
measuring 5 inches,
another side measuring
7 inches, and a third
side measuring 12 inches
condition E: one angle
measuring 30°, another
angle measuring 80°,
and the length of the
included side measuring
8 inches
condition F: one angle
measuring 40°, another
angle measuring 80°, and
a third angle measuring 60° I don't know how to do a pic, but it is no triangle one triangle and many triangle
Answer:
Condition A= 320 inches
Condition B= 190 Degrees F
Condition C= 2240 inches
Condition D= 350 inches
Condition E= 110 Degrees F 8 inches
Condition F= 180 Degrees F
Step-by-step explanation:
4 inches
8 inches
70 inches
60 D
40 D
90 D
4 inches
8 inches
70 D
5 inches
7 inches
12 inches
30 D
80 D
8 inches
40 D
80 D
60 D
Answer:
Condition A= 320 inches
Condition B= 190 Degrees F
Condition C= 2240 inches
Condition D= 350 inches
Condition E= 110 Degrees F 8 inches
Condition F= 180 Degrees F
Step-by-step explanation:
The coordinates of the point that is a reflection of Y(-4, -2) across the x-axis are (_,_)
The coordinates of the point that is a reflection of Y across the y-axis are (_,_) also anwser the top u know
Answer:
(-4,2)
Step-by-step explanation:
A store sells ground meat in small, medium, and large sizes. The weights of the small size packages have a mean weight of 1 pound and a standard deviation of 0.1 pound. If the distribution of weights for the small size packages of ground meat is approximately normally distributed, what is the best estimate of the probability that a randomly selected small size package has a weight less than 0.9 pound? Explain how you found your answer.
Answer:
15.87 %
Step-by-step explanation:
z = (.9-1)/.1 = -1
z score of -1 = .1587
The probability that a randomly selected small size package has a weight of less than 0.9 pounds is 15.87 %
We have given that,
A store sells ground meat in small, medium, and large sizes. The weights of the small size packages have a mean weight of 1 pound and a standard deviation of 0.1 pounds. If the distribution of weights for the small-size packages of ground meat is approximately normally distributed
What is the formula for the z-score?[tex]Z = \frac{x - \mu}{\sigma}[/tex]
Z = standard score
x = observed value
[tex]\mu[/tex] = mean of the sample
[tex]\sigma[/tex] = standard deviation of the sample
z = (0.9-1)/0.1 = -1
z of -1 = 0.1587
Therefore the value of the z-score is 0.1587.
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Which is true about this triangle?
Answer:
C=32°
because sum of three angles of triangles is 180°
Dave and Ellen are newly married and living in their first house. The yearly premium on their homeowner's insurance policy is $450 for the coverage they need. Their insurance company offers a 5 percent discount if they install dead-bolt locks on all exterior doors. The couple can also receive a 2 percent discount if they install smoke detectors on each floor. They have contacted a locksmith, who will provide and install dead-bolt locks on the two exterior doors for $50 each. At the local hardware store, smoke detectors cost $7 each, and the new house has two floors. Dave and Ellen can install them themselves.
Answer:
A. 4.44years
B. 1.5years
C. Yes
Step-by-step explanation:
a. Calculation to determine how many years will it take Dave and Ellen to earn back in discounts the cost of the dead-bolts
First step is to determine the Annual discount for dead-bolts using this formula
Annual discount for dead-bolts=Discount percent × Annual premium
Let plug in the formula
Annual discount for dead-bolts=0.05 × $450
Annual discount for dead-bolts=$22.50
Now let determine the Recovery period using this formula
Recovery period=Cost of dead-bolts / Annual discount for dead-bolts
Let plug in the formula
Recovery period= (2 × $50)/ $22.50
Recovery period=$100/$22.50
Recovery period= 4.44years
Therefore Assuming their insurance rates remain the same, how many years will it take Dave and Ellen to earn back in discounts the cost of the dead-bolts will be 4.44years
b. Calculation to determine How many years will it take Dave and Ellen to earn back in discounts the cost of the smoke detectors
First step is to calculate the Annual discount for smoke alarms using this formula
Annual discount for smoke alarms=Discount percent × Annual premium
Let plug in the formula
Annual discount for smoke alarms=0.02 × $450
Annual discount for smoke alarms=$9.00
Now let determine the Recovery period using this formula
Recovery period=Cost of smoke alarms / Annual discount for smoke alarms
Let plug in the formula
Recovery period=(2 × $7) / $9.00
Recovery period=$14/$9.00
Recovery period= 1.5 years
Therefore How many years will it take Dave and Ellen to earn back in discounts the cost of the smoke detectors will be 1.5years
C. YES, Based on the information I WOULD recommend Dave and Ellen to invest in the SAFETY ITEMS, if they plan to stay in that house for about 5 years reason been that a home that is equipped with HOME SAFETY ITEMS can help to prevent UNFORESEEABLE ACCIDENTS that may occur, which is why SAFETY ITEMS is vital for every home regardless of the recovery period.
