Answer:
c(t)=90+90×0,04t
c(t)=3,6t + 90
Question 1 ( point) A 64g sample of Germanium-66 is left undisturbed for 12.5 hours. At the end of that period, only 2.0g remain. How many half-lives transpired during this time period? half-lives Answer = Blank 1:
Answer:
2.5 half-lives
Step-by-step explanation:
Find [tex]t_{h}[/tex] in [tex]N(t)=N_{0}e^{-kt}[/tex] given [tex]N(t) = 2, N_{0} =64,t=\frac{25}{2}[/tex]
[tex]N(t)[/tex] is the amount after the time [tex]t[/tex], [tex]N_0[/tex] `is the initial amount, [tex]t_{h}[/tex] is the half-life
We know that after half-life there will be twice less the initial quantity:
[tex]N(t_{h})=\frac{N_{0} }{2}=N_{0}e^{kt_{h} }[/tex].
Simplifying gives [tex]\frac{1}{2} =e^{-kt_h} or k = -\frac{In(\frac{1}{2}) }{t_{h} } .[/tex]
Plugging this into the initial equation, we obtain that [tex]N(t)=N_{0}e^\frac{In(\frac{1}{2}) }{t_{h} }[/tex]or [tex]N(t)= N_{0} (\frac{1}{2})^\frac{t}{t_h}.[/tex]
Finally, just plug in the given values and find the unknown one.
From [tex]2=64(\frac{1}{2})^\frac{\frac{25}{2} }{t_h}[/tex], we have that [tex]t_h[/tex] = [tex]\frac{25 In (2)}{2 In (32)\\}[/tex]
So you should get: [tex]t_{h} =\frac{25 In (2)}{2 In (32)\\}=2.5.[/tex]
MARK ME AS BRAINLIEST IF YOU WISHThe number of half-lives that transpired during this time period is equal to 2.5 hours.
Given the following data:
Time = 12.5 hours.
Initial mass = 64 grams.
Remaining mass = 2.0 grams.
How to determine the number of half-lives.Mathematically, the amount of a radiocative element that is remaining after time (t-hours) is given by this formula:
[tex]ln(\frac{A}{A_0} )=ln(\frac{1}{2} )\frac{t}{H}[/tex]
Where:
A is the amount remaining.Ao is the initial amount.H is the half-life.t is the time.Substituting the given parameters into the formula, we have;
ln(2/64) = ln(1/2) × 12.5/H
-3.466 = -0.693 × 12.5/H
H = 12.5 × -0.693/-3.466
H = 12.5 × 0.1999
H = 2.5 hours.
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A bakery sold 210 vanilla cupcakes in a day, which was 42% of the total number of cupcakes sold that day. How many total cupcakes did the bakery sell that day?
PLEASE DONT SAY RANDOM ANSWERS ILL GIVE 15 POINTS
Answer:
88.2 is your answer.
Answer:500
Step-by-step explanation:on delta math
PLEASE HELP ITS DONE IN 16 HOURSSS!!!
question: A substance with 12 negatively charged atoms combined with a substance that has 10 positively charge atoms. What is the total charge of the substance when the atoms are combined?
answer options:
+22
-22
+2
-2
If the area of a circle is 50.25 meters what is the radius
Answer:
≈3.99938
Step-by-step explanation:
The sum of a number and six times its reciprocal is 10. Find the number
Answer:
two solutions work: x = 5 + [tex]\sqrt{19}[/tex] and x = 5 - [tex]\sqrt{19}[/tex]
Step-by-step explanation:
x + 6 ( 1/x ) = 10
x^2 + 6 = 10x
x^2 - 10x + 6 = 0
x = 5 + [tex]\sqrt{19}[/tex], 5 - [tex]\sqrt{19}[/tex]
Challenger elementary school has 800 students every Wednesday 12% of the students stay after school for the chess club. How many students attend the chess club on wednesdays?
Answer:
96 people
Step-by-step explanation:
i used a calculator
The side lengths of four triangles are listed below. Determine whether each triangle is a right triangle Choose Yes or No for each set of side lengths.
a. 4,5,6 Yes No
b. 5, 12, 13 Yes No
C. 8, 15, 17 Yes No
d. 10, 15, 20 Yes No
Answer:
yes, yes, no, no
Step-by-step explanation:
The results of a national survey showed that on average, adults sleep 6.3 hours per night. Suppose that the standard deviation is 1.6 hours. (a) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 3.1 and 9.5 hours. % (b) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 2.3 and 10.3 hours. % (c) Assume that the number of hours of sleep follows a bell-shaped distribution. Use the empirical rule to calculate the percentage of individuals who sleep between 3.1 and 9.5 hours per day. % How does this result compare to the value that you obtained using Chebyshev's theorem in part (a)
Answer:
a) 75%.
b) 84%
c) Within 2 standard deviations from the mean is 95%. The normal distribution has a higher percentage of observations closer to the mean than a non normal distribution, so this percentage is larger.
Step-by-step explanation:
Empirical Rule:
The Empirical Rule states that, for a normally distributed random variable:
Approximately 68% of the measures are within 1 standard deviation of the mean.
Approximately 95% of the measures are within 2 standard deviations of the mean.
Approximately 99.7% of the measures are within 3 standard deviations of the mean.
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].
In this question:
Mean: 6.3 hours
Standard deviation: 1.6 hours
(a) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 3.1 and 9.5 hours.
3.1 = 6.3 - 2*1.6
9.5 = 6.3 + 2*1.6
Within 2 standard deviations, so the minimum percentage is 75%.
(b) Use Chebyshev's theorem to calculate the minimum percentage of individuals who sleep between 2.3 and 10.3 hours.
How many standard deviations from the mean?
One standard deviation is 1.6
These measures are 10.3 = 6.3 = 6.3 - 2.3 = 4. This is k standard deviations, in which
[tex]k = \frac{4}{1.6} = 2.5[/tex]
The minimum percentage is:
[tex]100(1 - \frac{1}{k^{2}}) - 100(1 - \frac{1}{2.5^{2}}) = 84%[/tex]
So 84%.
(c) Assume that the number of hours of sleep follows a bell-shaped distribution. Use the empirical rule to calculate the percentage of individuals who sleep between 3.1 and 9.5 hours per day.
Within 2 standard deviations from the mean is 95%. The normal distribution has a higher percentage of observations closer to the mean than a non normal distribution, so this percentage is larger.
1 inch x 3/4 inch x 1/2 inch
Answer:
3/8
Step-by-step explanation:
Parents of children with developmental disorders can apply for federal funding, to help pay for psychosocial rehabilitation. A sociologist working for the annual Current Population Survey wants to know the percentage of applicants for this funding who are in poverty. She needs a sample of applicants from across the U.S., so she groups all of the applications by state and randomly selects applicants from each state. What sampling scheme did she use
Answer:
Stratified sampling
Step-by-step explanation:
key word "groups"
The sampling scheme did she used is stratified sampling.
What is stratified sampling?It is a method of sampling where the division of the population should be split into the smaller subgroup called a strata. The strata should be created depending upon on the members shared like the income etc. Here the sample should be needed for applicants for across the US also it randomly selects the applicants for each state.
So, The sampling scheme did she used is stratified sampling.
Learn more about a sample here: https://brainly.com/question/24526520
1. According to New Jersey Transit, the 8:00 a.m. weekday train from Princeton to New York
City has a 90% chance of arriving on time on a randomly selected day. Suppose this claim is
true. Suppose 6 days are chosen at random. Let X = the number of days on which the train
arrives on time.
(B) Find the mean of X. Interpret this value in context. SHOW YOUR WORK.
Find the length of arc AD. Use 3.14 for .
Round to the nearest tenth.
7.9 cm
B
66.4
C
[ ? ]cm
Enter
Answer:
Length of arc AD = 15.7 cm
Step-by-step explanation:
Length of arc = [tex]\frac{\theta}{360}(2\pi r)[/tex]
Here, θ = Central angle subtended by the arc
r = radius of the circle
From the picture attached,
Central angle subtended by arc AD = 360° - (180° + 66.4°)
= 113.6°
Length of arc AD = [tex]\frac{(113.6)}{360}(2\pi )(7.9)[/tex]
= [tex]\frac{113.6}{360}(2)(3.14)(7.9)[/tex]
= 15.655 cm
≈ 15.7 cm
Length of arc AD = 15.7 cm
Answer:
12.4
Step-by-step explanation:
Just did it.
A right rectangular prism has a length of 6 centimeters, a width of 7 centimeters, and a height of 5 centimeters.
What is the volume of the prism?
____cm3
a) 214
b) 197
c) 210
CORRECT ANSWER= BRAINLY!!
Answer: c is the answer
Step-by-step explanation: the formuals for volume is length x width x height, 6x7x5, which is 210
Answer: C
Step-by-step explanation: Easy, just do length x width x height(l x w h). So, 6x7x5 = 210
what's the fourth proportional of 0.2, 0.5, 6
Answer:
15
Step-by-step explanation:
a:b::c:d
a/b=c/d .......(eq 1)
let a=0.2, b=0.5, c=6, d=x
Not put values in eq 1
0.2/0.5 = 6/a
By cross multiplication we get:
0.2xa = 6x0.5
0.2a = 3
Dividing by 0.2 on both sides we get
0.2a/0.2 = 3/0.2
a = 15
Therefore The fourth proportional is 15
Given the following 4 numbers write a program that will determine which number is the smallest out of the 4.
Number 1 = 5, number 2 = 25, number 3 = 2, number 4 = 56
Answer:
2
Step-by-step explanation:
It's the smallest one.
How many digits will be in the quotient?
39) 4,641
1 digit
3 digits
2 digits
4 digits
How many arrangements are there of 12 distinct items?
Answer:
There are 479,001,600 arrangments of 12 distinct items.
Step-by-step explanation:
Arrangements of n items:
The number of possible arrangements of n itens is given by the factorial of n, that is:
[tex]A_{n} = n![/tex]
12 items:
[tex]A_{12} = 12! = 479001600[/tex]
There are 479,001,600 arrangments of 12 distinct items.
PLEASE HELP!!!!!! ILL GIVE BRAINLIEST *EXTRA 40 POINTS** !! DONT SKIP :((
Answer:
yes
Step-by-step explanation:
2 + 16(1) = 18
2+16 = 18
2(2) + 11(1) = 15
4+11=15
what shape can be formed from the following net
Answer:
square pyramid
Step-by-step explanation:
Answer:
star
Step-by-step explanation:
A square painting has a side length of 13 inches.
What is the area of the painting?
The area of the painting is
square inches.
Answer:
Step-⚫️_by-step explanation:
reasons why students fail exams
Whats the answer to these? (These are called Proper fractions.)
Jeremiah ran for 3/10 of a mile and then walked another 2/5 of a mile. How far did he travel in all?
Daniel read 4/5 books and Edgar read 1/2 books. How many more books did Daniel read than Edgar?
Jared drove 2/8 miles to the restaurant. He drove another 1/4 miles to the mall. How many miles did he drive in all?
Answer:
1: 7/10
2: 3/10
3: 4/8 (2/4 or 1/2 if you need to simplify it)
Step-by-step explanation:
1: Convert 2/5 to tenths by multiplying the denominator and numerator by two. 3/10 plus 4/10 is 7/10
2: Convert 4/5 and 1/2 to tenths.
4/5 is going to be 8/10, 1/2 is going to be 5/10.
Subtract 5/10 from 8/10 to get 3/10
3: Convert 1/4 to eighths to get 2/8. Then add 2/8 and 2/8 to get 4/8.
... Helppppp!! will mark brainiest
Answer: The answer is C
Step-by-step explanation:
C is the answer because the base is +2 and the coefficent is 1/2 which is rise over run so you go up one space and to the right two spaces.
Please help!!! Find the side length of a
Answer:
B
Step-by-step explanation:
√c^2-b^2
√15^2-9^2
√225-81
√144
= 12
B
25 POINTS
Solve this equation PLEASE AND STEPS
4=1/2(2x+4+x)(x-2)
Answer:
x=−2, 2.6666
Step-by-step explanation:
Let's solve your equation step-by-step.
4=(1/2(2x+4+x))(x−2)
Step 1: Simplify both sides of the equation.
4=3/2 x2−x−4
Step 2: Subtract 3/2x^2-x-4 from both sides.
4−(3/2 x2−x−4)=
3/2 x2−x−4−(3/2 x2−x−4)
−3/2 x2 +x+8=0
For this equation: a=-1.5, b=1, c=8
−1.5x2+1x+8=0
Step 3: Use quadratic formula with a=-1.5, b=1, c=8.
x=−b±√b2−4ac
2a
x=−(1)±√(1)2−4(−1.5)(8)
2(−1.5)
x=−1±√49
−3
x=−2,2.66666666666666666666666666666
Francisco took $20.00 to the mall. He found a DVD he wanted on sale for 18.50. The sales tax rate in his state is 8%. DOe he have enough money to buy the DVD, including tax?
A. No he need an addional $1.48
B. Yes, and he has $0.02 left over.
C. No, he need an additional $13.30.
D. Yes, and he has $1.50 left over.
Please I need help it’s an emergency
Answer:
the answer is 36
Step-by-step explanation:
beacuse if we use the pythagorean theorem for 9 and 12 we get 15 which means that the perimeter is P=9+15+12=36
Factorise
1) 9a^2 - 6a
Answer:
[tex]3a(3a - 2)[/tex]
Step-by-step explanation:
[tex]3(3a ^{2} - 2a) \\a(3a - 2) [/tex]
7. Find the inverse of f(x) = -2x + 10. Please show work.
Answer- y = - x/2 + 5
Step by step - Replace f (x) with y.
Y = - 2x + 10
Interchange the variables.
x= -2y + 10
Solve for y.
Y= x/2 +5
Which scatterplot demonstrates the strongest relationship between two quantitative variables?
A graph has x on the x-axis, and y on the y-axis. Points are scattered throughout the graph.
A graph has x on the x-axis, and y on the y-axis. Points curve up and then down in a line.
A graph has x on the x-axis, and y on the y-axis. Points increase loosely together.
A graph has x on the x-axis, and y on the y-axis. Points decrease loosely together.
The scatterplot demonstrates the strongest relationship is, a graph has x on the x-axis, and y on the y-axis. Points increase loosely together.
What is Correlation coefficient of scatterplot?The correlation coefficient of scatterplot is used to demonstrate the relationship between variables.
When two variables increases together, they are said to have positive correlation.
When one is increasing and another is decreasing, they are said to have negative correlation.
When most of data points form a straight line or lies close to the straight line, it indicates strong linear correlation.
From the given options;
Option A, zero correlation
Option B, less than 1
Option C, 1 or greater than 1
Option D, -1 or less than 1
Thus, the scatterplot demonstrates the strongest relationship between two quantitative variables is option C, "a graph has x on the x-axis, and y on the y-axis. Points increase loosely together".
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