one sixth of a number?
The rate at which a quantity M of a certain radioactive substance decays is proportional to the amount of the substance present at a given time. Which of the following is a differential equation that could describe this relationship?
1. dM/dt = -3.72 t^2
2. dM/dt = -0.11M
3. dM/dt = 0.08 t^2
4. dM/dt = 1.2M
Answer:
2. dM/dt = -0.11M
Step-by-step explanation:
Differential equations for proportional amouts:
A differential equation for proportional amounts is given by:
[tex]\frac{dx}{dt} = ax[/tex]
In which a is the constant rate. If the amount increases, a is positive. If it decays, b is positive.
In this question:
Decays, so a < 0.
Proportional to the amount of the substance present at a given time, which means that a multiplies the amount M.
This means that the correct answer is given by option 2.
K Write an expression for the sequence of operations described below. add y to z, then multiply 3 by the result
Answer:
3(y+z)
Step-by-step explanation:
y+z is added first so it is in parentheses and then multiply by the 3
1. Force is a push or a
upon an object
A heat
C. pull
B. motion
D. transfer
2 Which is needed to make an object move?
A density
C. porous
B. force
D. non-porous
Answer:
1. C
2.B
Step-by-step explanation:
Force is a push or a pull.. can be a twist too
to make an object move you have to apply force by pushing of pulling the object.
A spinner has five sections labeled a,b,c,d,e. The spinner is spun 45 times
Answer:
40
Step-by-step explanation: pls I need points make brainpy
An inclined walkway leading to a new building is to rise 11 inches for each horizontal distance of 22 feet. Write this slope as a grade. (Round to the nearest tenth of a percent if necessary.)
Answer:
4.2%
Step-by-step explanation:
The horizontal distance, x (Run) = 22 feets
Rise, vertical distance, y = 11 inches
The slope is the ratio of the vertical to the horizontal distance, Rise to Run
Slope = Rise / Run
Converting to the same unit ;
Foot to inches
1 foot = 12 inches
Hence, x = 22 feets = (12 * 22) = 264 inches
Slope = Rise / Run = 11 / 264 = 0.04167
Slope = 0.04167 * 100% = 4.167%
the ratio of the corresponding sides of two similar triangles is 2:5 the sides of the smaller triangle is 6mm 8mm and 12mm what is the perimeter of the larger triangle?
Answer:
65
Step-by-step explanation:
using the ratio we can find the side lengths of the other triangle.
since it is 2:5
6:x=2:5
so x = 15(first side)
8:x=2:5
so x = 20(second side)
12:x=2:5
x=30(third side)
so then we add them up
15+20+30
65
hope this was helpful
Find the value of x. 7+8x+45+80
Answer:
=8x+132
Step-by-step explanation:
Combine Like Terms:
=7+8x+45+80
=(8x)+(7+45+80)
=8x+132
Give me brainllest plz T-T
Suppose {an) is an arithmetic sequence with a16=12 and a7=30. Find a9.
Answer:
a9 = 26
Step-by-step explanation:
nth term of an arithmetic sequence an = a + (n-1)d
a16 = a+15d = 12.... 1
a7 = a+6d = 30.....2
Subtract
15d - 6d = 12 - 30
9d = -18
d =-18/9
d = -2
Substitute d = -2 into 1
a + 15d = 12
a+15(-2) = 12
a - 30 = 12
a = 12 + 30
a = 42
Get a9;
a9 = a+8d
a9 = 42+8(-2)
a9 = 42 - 16
a9 = 26
hence the 9th term of the sequence is 26
(2, -16)
plug in the correct variables in the equation below
y = mx + b
The Answer Is Y=-8x
This is because x is multiplied by -8 to find y.
A laser pointer in the shape of a cylinder is 13 centimeters long with a radius of 0.75 centimeters.
What is the volume of the laser pointer?
Express your answer in terms of π and round to the nearest cubic centimeter. PLS HELP NOOO LINKS pls <3
Answer:
V = 23 cm 3
Step-by-step explanation:
A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at least 754 hours. A random sample of 29 light bulbs has a mean life of 737 hours. Assume the population is normally distributed and the population standard deviation is 59 hours. At α=0.08, do you have enough evidence to reject the manufacturer's claim? Complete parts (a) through (e)
Answer:
The calculated test |Z| = |-1.55| >1.405 at 0.08 level of significance
The null hypothesis is rejected at a 0.08 level of significance.
An Alternative hypothesis is accepted
A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at most 754 hour
Step-by-step explanation:
Step(i):-
Given that the mean life of a certain type of light bulb is at least 754 hours
Given that the random sample size 'n' =29
Given that the mean life of sample x⁻ = 737
Given that the standard deviation of the Population = 59
Step(ii):-
Null hypothesis: H₀: μ≥ 754
Alternative Hypothesis:H₁: μ≤ 754
Test statistic
[tex]Z = \frac{x^{-}-mean }{\frac{S.D}{\sqrt{n} } }[/tex]
[tex]Z = \frac{737-754 }{\frac{59}{\sqrt{29} } }[/tex]
Z = -1.55
The calculated test |Z| = |-1.55| >1.405 at 0.08 level of significance
The null hypothesis is rejected at 0.08 level of significance
Final answer:-
The calculated test |Z| = |-1.55| >1.405 at 0.08 level of significance
The null hypothesis is rejected at a 0.08 level of significance.
A light bulb manufacturer guarantees that the mean life of a certain type of light bulb is at most 754 hour
Select the statement that correctly describes a normal distribution.
a. It is a negatively skewed distribution, as the extreme values are less than the median.
b. It is a symmetric distribution, as the mean and the median are the same.
c. It is a positively skewed distribution, as the extreme values are greater than the median.
d. It is a uniform distribution, as all of the values have equal frequency.
Answer:
b. It is a symmetric distribution, as the mean and the median are the same.
Step-by-step explanation:
Normal distribution:
The biggest characteristic of the normal distribution is that it's symmetric, that is, 50% of the values are below the mean and 50% are above, which means that the mean is the same as the median.
This means that the correct answer is given by option b.
If the given figure is rotated 180° around the origin, what are the new coordinates of point Z?
please I really need help with this.
Answer:
New coordinates of the point Z are (-6, 9)
Step-by-step explanation:
If a point (x, y) is rotated 180° about the origin, coordinates of the image point is given by the rule,
(x, y) → (-x, -y)
Coordinates of the vertex Z → (6, -9)
Following the same rule,
Z(6, -9) → Z'(-6, 9)
Therefore, coordinates of the new (image) point will be (-6, 9).
A ribbon is 24 inches long. You need to cut it into pieces so that all the pieces are the same length. a. Can you cut the ribbon into 5-inch pieces?
Answer:
no
Step-by-step explanation:
no, because 24 is not divisible by five. If you divide 24/5, you will be left with 4+4/5, and you can't have 4/5 of a piece and have them all be the same length
9. What is 30% of 60?*
8
18
28
38
Answer:
It's 18
Step-by-step explanation:
30/100 x 60/1
180/100 =18
Answer:
18
Step-by-step explanation:
Here. We are going to multiply both sides of the equation by this fraction 100 over 30 100 over 30.
IF A FUNCTION f(x) is defined AS 5x^2-3x+3, what is the expression for
Answer: C. 10x-3
Step-by-step explanation: I got this question correct on Edmentum.
The value of the expression will be 10x – 3. Then the correct option is C.
What is the limit?The value that approaches the output for the given input value. Limits are a very important tool in calculus.
The function is defined as,
f(x) = 5x² – 3x + 2
Then the value of the expression will be
[tex]\rightarrow \displaystyle \lim_{h \to 0} \dfrac{f(x+h)-f(x)}{h}[/tex]
Substitute the value of the function, then the value of the expression will be
[tex]\rightarrow \displaystyle \lim_{h \to 0} \dfrac{5(x+h)^2 - 3(x + h) + 3- 5x^2 + 3x - 3}{h}\\\\\\\rightarrow \displaystyle \lim_{h \to 0} \dfrac{5x^2 + 5h^2 + 10xh - 3x - 3h + 3- 5x^2 + 3x - 3}{h}\\\\\\\rightarrow \displaystyle \lim_{h \to 0} \dfrac{ 5h^2 + 10xh - 3h }{h}\\[/tex]
Simplify the equation further, then we have
[tex]\rightarrow \displaystyle \lim_{h \to 0} 5h + 10x - 3 \\[/tex]
Substitute the value of the h = 0, then the value of the expression will be
⇒ 5(0) + 10x – 3
⇒ 10x – 3
Then the correct option is C.
More about the limit link is given below.
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If f(x) = x - 1 and g(x) = x3, what is (gºf)(8)?
Answer:
343
Step-by-step explanation:
f(x) = x - 1 and g(x) = x^3
g(f(8))
First find f(8) = f(8-1) = 7
Then find g(7) = 7^3 = 343
g(f(8) = 343
Answer:
I will assume that you meant to type (g o f)(8).
First we find f(8).
f(8) = 8 - 1 or 7.
We now find g(f(8)), which means g(7).
g(7) = 7^3 or 343
(g o f)(8) = 343:
PLEASE TELL ME PLEASE
Answer: D!! also 35% are spotted
Answer:
The answer is a.
Step-by-step explanation:
This is because the percent is out of 100 and the flock of spotted sheep is placed in the numerator.
Year 1= $550
Year 2 = $950
Year 3 = $1120
Year 4= $1190
Initial investment is $980
My discount rate = 9.4%. What is my discounted period?
I need the discounted period
Answer:
sorry I need points
Step-by-step explanation:
so so so sorry :(
Write an equation for the sum of x and 3 minus 2 is 12
Answer:
x + (3-2) = 12
Step-by-step explanation:
x + (3-2) = 12
or x + 1 = 12
so x = 11
For his birthday , Aaron received four stamps for his collection . his collection already contained eight times that number of stamps. Before pasting the stamps into albums , Aaron divide them equally into three envelope. Which numerical expression models the number of stamps in each envelope? A 12÷3 B 4+32÷3 C (4+32)÷3 D 12×4÷4
Answer:
C
Step-by-step explanation:
Aaron received four stamps. He already had eight times as much. 32 + 4. Before pasting the stamps into albums, Aaron divides them equally into three envelopes. (32 + 4) ÷ 3.
Helpppppp pleaseeeeeeee
Answer:
16 2/3
Step-by-step explanation:
Would greatly appreciate the help with both A and B
The first step in the process for factoring the trinomial x2-3x - 40
Answer:
List all the factors of 40
Step-by-step explanation:
Bob the builder eat no fewer then three donuts. What is the inequality?
Answer:
3
Step-by-step explanation:
I think
Answer:
less than or equal to 3
Step-by-step explanation:
PLZ HELP I NEED AWNSERS ASAP
a statistical question anticipates that answers will vary. which of these are examples of statistical questions?
A) how many computers are in the school's lab?
B) how many letters are in the wrong direction?
C) what are the favorite books of each member of the book club?
D) how many people volunteered to help at the community's Christmas
E) how many video games were purchased last year by each student in Mr.hills math class
E.
It gives a very precise question which will give much data.
Question: Edwin usually makes 20 cookies with this recipe, but only wants 5 cookies.
How much is 1/2 teaspoon of vanilla to make 5 cookies?
(PLEASE HELP!!)
Answer:
1/8 teaspoon of vanilla is needed to make 5 cookies
Step-by-step explanation:
1) 1/2 teaspoon of vanilla makes 20 cookies
2) you only need 5 cookies which is 1/4 as many cookies as before
3) you must 1/4 your recipe
4) 1/2 divided by 4 = 1/8
Jon throws a ball into the air off a platform. The height of the ball is given by y equal minus 2 x to the power of 2 plus 11 x plus 21 where y is the height, in feet, above the ground when the ball has traveled a horizontal distance of x feet. What is the factored form of the expression that could be used to find out how far the ball has traveled horizontally when it hits the ground?
A. (x+7)(-2X+3)
B. (x-7)(-2x-3)
C.(2x+7)(x+3)
D. (2x-7)(-x-3)
Answer:
B (-2x - 3 )(x - 7) = (x - 7)(-2x - 3 )
Step-by-step explanation:
y = -2x² + 11x + 21
find x when y is zero (the ground)
(-2x - 3 )(x - 7) = 0
(-2x - 3 ) = 0, (x - 7) = 0
x = -1.5 and x = 7 since Jon did not throw the ball behind him (remember he is standing on a platform) the only possible answer is 7 feet in front of him, but they the question didn't ask for x, so I would answer B. The answer I got and multiplicans are in reverse order from their choice.
The factored form of the expression that could be used to find out how far the ball has traveled horizontally when it hits the ground is (x-7)(-2x-3)
What is quadratic equation?A quadratic equation is a second-order polynomial equation in a single variable x , ax² +bx+c=0. with a ≠ 0 .
Given that Jon throws a ball into the air off a platform.
The height of the ball is given by y equal minus 2 x to the power of 2 plus 11 x plus 21
y= -2x² + 11x + 21.
Let us factor out the equation by quadratic equation
-2x² + 11x + 21
When we factor out the equation becomes as (x-7)(-2x-3)
Let us verify the solution by applying distribution property
-2x²-3x+14x+21
-2x²+11x+21
Hence, (x-7)(-2x-3) is the factored form of the expression that could be used to find out how far the ball has traveled horizontally when it hits the ground.
To learn more on Quadratic equation click:
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PLZ FULL ANSWER
Maria has the following scores on exams in her social studies class: 86, 75, 97, 58, 94, and 58. Find the mean, median, and mode of the scores. Should Maria’s social studies teacher use the mean, median, or mode of the exam scores to convince Maria that she needs to study more regularly for her exams?
Answer:
The mean is 78
The Median is 80.5
And The Mode is 58.
Step-by-step explanation:
(Mean) 86,75,97,58,94, and 58 equal 468. Divide it by 6 (The Total Of All The Numbers) and it gives you 78.
(Mode) Find the number that occurs the most which would be 58.
(Median) Put the numbers in order. Order: 58,58,75,86,94,97. Next, your supposed to find the number in the middle, but since there are 2(75 and 86.)
Add them together and you get 161. After that, divide them by 2 and it'll give you 80.5
By the way, if the number of numbers in the problem add up to be an even number, divide it by 2 and find the average. If it's odd, divide it by 2 and round it up to get to the median.
So yes, the teacher should use the scores to convince Maria that she needs to study more regularly for her exams.
The mean, median, or mode of the exam scores is 78, 86 and 58
What is Mean, median and Mode?The mean (average) of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set.
The median is the middle value when a data set is ordered from least to greatest.
The mode is the number that occurs most often in a data set.
Given data: 58, 58, 75, 86, 94, 97
1. Mean= sum of observation/ Total number observation
= 58+58+75+86+94+97/6
=468/6
=78
2. Median,
Since, n is even
median= (n/2)+ 1
= 6/2 + 1
= 3+1
=4 th term= 86
3. Mode: Mode is the repeating data
mode= 58
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