Answer:
[tex]y(1) = 0.5518[/tex]
Step-by-step explanation:
Given the differential equation [tex]e^{t} \frac{dy}{dt} +e^{t}y = t[/tex]
From the equation;
[tex]e^{t} (\frac{dy}{dt} +y) = t\\\frac{dy}{dt} +y = \frac{t}{e^{t}} \\[/tex]
The resulting equation is a first order differential equation in the form
dy/dt + p(t)y = q(t)
The solution to the DE will be in the form yI = [tex]\int\limits q(t)*I\, dt[/tex] where I is the integrating factor expressed as [tex]I = e^{\int\limits p(t) \, dt }[/tex]
From the DE above p(t ) = 1 and q(t) = [tex]\frac{t}{e^{t} }[/tex]
[tex]I = e^{\int\limits1 \, dt }\\I = e^{t }\\[/tex]
The solution to the DE will become
[tex]y e^{t } = \int\limits e^{t } *\frac{t}{e^{t } } \, dt\\y e^{t } = \int\limits{t} \, dt \\y e^{t } = \frac{t^{2} }{2} + C[/tex]
If y(0) = 1 then;
[tex]1 e^{0 } = \frac{0^{2} }{2} + C\\1 = C[/tex]
[tex]y e^{t } = \frac{t^{2} }{2} + 1\\y(t) = \frac{1}{e^{t } } (\frac{t^{2} }{2} + 1)[/tex]
The value of y(1) will be expressed as;
[tex]y(1) = \frac{1}{e^{1} } (\frac{1^{2} }{2} + 1)\\y(1) = \frac{1}{2e}+\frac{1}{e}\\ y(1) = \frac{3}{2e}[/tex]
[tex]y(1) = \frac{3}{5.4366} \\y(1) = 0.5518[/tex]
A professor would like to test the hypothesis that the average number of minutes that a student needs to complete a statistics exam has a standard deviation that is less than 5.0 minutes. A random sample of 15 students was selected and the sample standard deviation for the time needed to complete the exam was found to be 4.0 minutes. Using α = 0.05, the conclusion for this hypothesis test would be that because the test statistic is
Answer:
[tex]\chi^2 =\frac{15-1}{25} 16 =8.96[/tex]
The degrees of freedom are given by:
[tex] df = n-1 = 15-1=14[/tex]
The p value for this case would be given by:
[tex]p_v =P(\chi^2 <8.96)=0.166[/tex]
Since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not ignificantly lower than 5 minutes
Step-by-step explanation:
Information given
[tex]n=15[/tex] represent the sample size
[tex]\alpha=0.05[/tex] represent the confidence level
[tex]s^2 =16 [/tex] represent the sample variance
[tex]\sigma^2_0 =25[/tex] represent the value that we want to verify
System of hypothesis
We want to test if the true deviation for this case is lesss than 5minutes, so the system of hypothesis would be:
Null Hypothesis: [tex]\sigma^2 \geq 25[/tex]
Alternative hypothesis: [tex]\sigma^2 <25[/tex]
The statistic is given by:
[tex]\chi^2 =\frac{n-1}{\sigma^2_0} s^2[/tex]
And replacing we got:
[tex]\chi^2 =\frac{15-1}{25} 16 =8.96[/tex]
The degrees of freedom are given by:
[tex] df = n-1 = 15-1=14[/tex]
The p value for this case would be given by:
[tex]p_v =P(\chi^2 <8.96)=0.166[/tex]
Since the p value is higher than the significance level we have enough evidence to FAIL to reject the null hypothesis and we can conclude that the true deviation is not ignificantly lower than 5 minutes
objective: Solve applications involving problem-s...
1 of 21 (0
1.1.A-4
Cookies are sold singly or in packages of 8 or 24. With this packaging, how many
ways can you buy 48 cookies?
Step-by-step explanation:
With the packaging of 8
48 cookies = 48 ÷ 8 = 6 boxes
With the packaging of 24
48 cookies = 48 ÷ 24 = 2 boxes
how many types of progression in mathematics?
A survey was conducted that asked 1003 people how many books they had read in the past year. Results indicated that x= 14.8 Books & S= 16.6 books. construct a 95% confidence interval for the mean number of books read. Interpret the interval.
construct a 95% confidence interval for the mean number of books people read and interpret the results. Select the correct choice below and fill in the answer boxes to complete your choice.
a) if repeater samples are taken, 95% of them will have a sample mean between _______and __________.
b) there is a 95% chance that the true me number of books read is between ________ and ________.c) there is 95% confidence that the population mean number of books read is between __________ and _____.
Answer:
c) there is 95% confidence that the population mean number of books read is between 13.77 and 15.83.
Step-by-step explanation:
We have to calculate a 95% confidence interval for the mean.
The population standard deviation is not known, so we have to estimate it from the sample standard deviation and use a t-students distribution to calculate the critical value.
The sample mean is M=14.8.
The sample size is N=1003.
When σ is not known, s divided by the square root of N is used as an estimate of σM:
[tex]s_M=\dfrac{s}{\sqrt{N}}=\dfrac{16.6}{\sqrt{1003}}=\dfrac{16.6}{31.67}=0.524[/tex]
The degrees of freedom for this sample size are:
[tex]df=n-1=1003-1=1002[/tex]
The t-value for a 95% confidence interval and 1002 degrees of freedom is t=1.96.
The margin of error (MOE) can be calculated as:
[tex]MOE=t\cdot s_M=1.96 \cdot 0.524=1.03[/tex]
Then, the lower and upper bounds of the confidence interval are:
[tex]LL=M-t \cdot s_M = 14.8-1.03=13.77\\\\UL=M+t \cdot s_M = 14.8+1.03=15.83[/tex]
The 95% confidence interval for the mean number of books read is (13.77, 15.83).
This indicates that there is 95% confidence that the true mean is within 13.77 and 15.83. Also, that if we take multiples samples, it is expected that 95% of the sample means will fall within this interval.
Questions 16-17. Suppose a tortoise is 1000 feet from the ocean. Each day the tortoise travels three-fifths of the remaining distance to the ocean. Use this information to: Construct a model that represents the remaining distance that the tortoise must travel to reach the ocean.
Answer:
r(n) = 1000·(2/5)^n
Step-by-step explanation:
Since the tortoise travels 3/5 the remaining distance, the remaining distance at the end of the day is 2/5 of what it was at the beginning of the day. So, the function can be modeled by an exponential with a "growth" factor of 2/5:
r(n) = 1000·(2/5)^n
where r(n) is the number of remaining feet after n days of travel.
Which value of x makes 7+5(x-3)=227+5(x−3)=227, plus, 5, left parenthesis, x, minus, 3, right parenthesis, equals, 22 a true statement? Choose 1 answer:
Answer:
7 + 5(x - 3) = 22
5(x - 3) = 15
x - 3 = 3
x = 6
Answer:
x = 6
Step-by-step explanation:
Step 1: Distribute 5
7 + 5x - 15 = 22
Step 2: Combine like terms
5x - 8 = 22
Step 3: Add 8 to both sides
5x = 30
Step 4: Divide both sides by 5
x = 6
In a race, Brian Collins has to cross 10 hurdles. The probability that he clears a hurdle is 2/3. Find P(clears all hurdles).
Answer:
1024/59049
Step-by-step explanation:
P( clear hurdle) = 2/3
There are 10 hurdles
P ( clear all hurdles) = P( clear hurdle) * P( clear hurdle)...... 10 times
= 2/3 * 2/3 *....... 10 times
= (2/3) ^ 10
=1024/59049
Answer:
1024/59049, 1.7%
Step-by-step explanation:
One way to do it would to be simply multiply 2/3 by itself 10 times
2/3 x 2/3 x 2/3 x 2/3 and so on
That would be a really long equation so instead we can use exponents to shorten it. We can simply just do 2^10/3^10
2^10=1024
3^10=59049
1024/59049, 1.7%
Alexandra has $15 to buy drinks for her friends at the baseball game. Soda
costs $2.75 and bottled water costs $2.00. This relationship can be
represented by the inequality 2758+2w $ 15. Three of Alexandra's friends
asked for water. Which inequality represents the number of sodas she can
buy?
A. OS 85 3.27
B. 85 3.27
C. OSSS3
D. 853
Answer:
C
Step-by-step explanation:
write an equation for the costs:
if x is the number of sodas
and y is the number of waters
2.75x + 2y <= 15
(<= is less than or equal to)
if we substitute 3 for y
we get 2.75x + 2(3) <= 15
2.75x + 6 <= 15
2.75x <= 9
9 / 2.75 = 3.2727
however, you cannot buy part of a soda
so, round to 3
you also cannot buy negative sodas
so, the answer is C
Right Angle Trigonometry
Applicatio
5 of 10
Round your answer to one decimal place.
Type in your response.
The angle between the string attached to a flying kite
and the ground is 60°
How far above the ground, in feet, is the kite if 220 ft
of string have been let out?
TT
Clear
Done
BA
220
760°
A
с
Menu
Answer:
Step-by-step explanation:
BC/220=sin 60
BC=220 sin 60=220×√3/2=110√3≈190.5 ft
Answer:
190.5 ft
Step-by-step explanation:
For the 60-deg angle, BC is the opposite leg. AB is the hypotenuse.
The trig ratio that relates the opposite leg to the hypotenuse is the sine ratio.
[tex] \sin A = \dfrac{opp}{hyp} [/tex]
[tex] \sin 60^\circ = \dfrac{BC}{220} [/tex]
[tex] BC = 220 \sin 60^\circ [/tex]
[tex] BC = 190.5 [/tex]
which equation represents the graph function?
Answer:
[tex]\displaystyle y=-\frac{1}{3}x+3[/tex]
Step-by-step explanation:
First, notice that since the graph of the function is a line, we have a linear function.
To find the equations for linear functions, we need the slope and the y-intercept. Recall the slope-intercept form:
[tex]y=mx+b[/tex]
Where m is the slope and b is the y-intercept.
We are given the point (0,3) which is the y-intercept. Thus, b = 3.
To find the slope, we can use the slope formula:
[tex]\displaystyle m=\frac{\Delta y}{\Delta x} =\frac{2-3}{3-0}=-1/3[/tex]
Therefore, our equation is:
[tex]\displaystyle y=-\frac{1}{3}x+3[/tex]
The heights of American men are normally distributed. If a random sample of American men is taken and the confidence interval is (65.3,73.7), what is the sample mean x¯? Give just a number for your answer. For example, if you found that the sample mean was 12, you would enter 12.
Answer:
69.5Step-by-step explanation:
Given the confidence interval of the heights of american heights given as (65.3,73.7);
Lower confidence interval L = 65.3 and Upper confidence interval U = 73.7
Sample mean will be the average of both confidence interval . This is expressed mathematically as [tex]\overline x = \frac{L+U}{2}[/tex]
[tex]\overline x = \frac{65.3+73.7}{2}\\\overline x = \frac{139}{2}\\\overline x = 69.5[/tex]
Hence, the sample mean is 69.5
Brainliest for the correct awnser!!!!! Which of the following is the product of the rational expressions shown below?
Answer:
A.
Step-by-step explanation:
Multiply straight across:
[tex]\frac{2}{x+1}\cdot \frac{5}{3x}=\frac{10}{3x(x+1)}[/tex]
Simplify:
[tex]=\frac{10}{3x^2+3x}[/tex]
This cannot be simplified further.
Answer:
[tex] \boxed{\sf \frac{10}{3 {x}^{2} + 3x}} [/tex]
Step-by-step explanation:
[tex] \sf Expand \: the \: following: \\ \sf \implies \frac{2}{x + 1} \times \frac{5}{3x} \\ \\ \sf \implies \frac{2 \times 5}{3x(x + 1)} \\ \\ \sf 2 \times 5 = 10 : \\ \sf \implies \frac{ \boxed{ \sf 10}}{3x(x + 1)} \\ \\ \sf 3x(x + 1) = (3x)(x) + (3x)(1) : \\ \sf \implies \frac{10}{ \boxed{ \sf (3x)(x) + (3x)(1)}} \\ \\ \sf (3x)(x) = 3 {x}^{2} : \\ \sf \implies \frac{10}{ \boxed{ \sf 3 {x}^{2}} + (3x)(1) } \\ \\ \sf (3x)(1) = 3x : \\ \sf \implies \frac{10}{3 {x}^{2} + 3x} [/tex]
Find the perimeter of the rhombus below, given that a=9 and b=15. Round your answer to one decimal place, if necessary.
Answer: 35.0 units long.
Step-by-step explanation:
You can treat a rhombus as four right triangles, where there is a short side, a long side, and a hypotenuse.
The hypotenuse of a right triangle inside a rhombus will always be on the exterior.
To find the hypotenuse of one of the right triangles, use the Pythagorean theorem:
[tex]a^2 + b^2 = c^2[/tex]
We are given that a = 9 and b = 15, but in order to get the values needed for the theorem, we must divide them by 2 in order to get the sides for the triangles.
9 / 2 = 4.5, 15 / 2 = 7.5
Then, you can substitute your values into the Pythagorean theorem:
[tex]4.5^2 + 7.5^2 = c^2\\\\20.25 + 56.25 = 76.5\\\\c^2 = 76.5\\c = 8.7464[/tex]
Knowing that one of the external sides is 8.7464 units long, you can then multiply that value by 4 to get your perimeter, as there are four identical sides forming the perimeter:
8.7464 * 4 = 34.9856. Rounded: 35.0
¿Cuál serie numérica tiene como regla general Xn = 2n +1?
a. 3, 5, 7, 9
b. 2, 4, 5, 8
c. 4, 6, 8,10
d. 2, 3, 4, 5
Answer:
The series of numbers that correspond to the general rule of [tex]X_n=2n+1[/tex] is {3, 5, 7, 9}.
Step-by-step explanation:
We are given with the following series options below;
a. 3, 5, 7, 9
b. 2, 4, 5, 8
c. 4, 6, 8,10
d. 2, 3, 4, 5
And we have to identify what number series has a general rule as [tex]X_n=2n+1[/tex].
For this, we will put the values of n in the above expression and then will see which series is obtained as a result.
So, the given expression is ; [tex]X_n=2n+1[/tex]
If we put n = 1, then;
[tex]X_1=(2\times 1)+1[/tex]
[tex]X_1 = 2+1 = 3[/tex]
If we put n = 2, then;
[tex]X_2=(2\times 2)+1[/tex]
[tex]X_2 = 4+1 = 5[/tex]
If we put n = 3, then;
[tex]X_3=(2\times 3)+1[/tex]
[tex]X_3 = 6+1 = 7[/tex]
If we put n = 4, then;
[tex]X_4=(2\times 4)+1[/tex]
[tex]X_4 = 8+1 = 9[/tex]
Hence, the series of numbers that correspond to the general rule of [tex]X_n=2n+1[/tex] is {3, 5, 7, 9}.
Suppose 150 students are randomly sampled from a population of college students. Among sampled students, the average IQ score is 115 with a standard deviation of 10. What is the 99% confidence interval for the average IQ of college students? Possible Answers: 1) A) E =1.21 B) E = 1.25 C) E =2.52 D) E = 2.11 2) A) 112.48 < μ < 117.52 B) 113.79 < μ < 116.21 C) 112.9 < μ < 117.10 D) 113.75 < μ < 116.3
Answer:
99% confidence interval for the mean of college students
A) 112.48 < μ < 117.52
Step-by-step explanation:
step(i):-
Given sample size 'n' =150
mean of the sample = 115
Standard deviation of the sample = 10
99% confidence interval for the mean of college students are determined by
[tex](x^{-} -t_{0.01} \frac{S}{\sqrt{n} } , x^{-} + t_{0.01} \frac{S}{\sqrt{n} } )[/tex]
Step(ii):-
Degrees of freedom
ν = n-1 = 150-1 =149
t₁₄₉,₀.₀₁ = 2.8494
99% confidence interval for the mean of college students are determined by
[tex](115 -2.8494 \frac{10}{\sqrt{150} } , 115 + 2.8494\frac{10}{\sqrt{150} } )[/tex]
on calculation , we get
(115 - 2.326 , 115 +2.326 )
(112.67 , 117.326)
Identify the segments that are parallel, if any, if ∠ADH≅∠ECK
Answer:
DF and CG
Step-by-step explanation:
Two or more segments are said to be parallel is the angle between them is [tex]180^{0}[/tex]. While two segments are said to be perpendicular when the angle between them is [tex]90^{0}[/tex].
The given figure is a parallelogram. A parallelogram is a quadrilateral with a pair of parallel opposite sides.
In the given question if ∠ADH ≅ ∠ECK , then the parallel segment would be DF and CG.
HELP !!!..... ASAP PLS
Step-by-step explanation:
the average change H = Δy/ Δx
so H = ( f(4) - f(2) )/ (4 -2) = ( 0 -1 ) / 2 = -1/2
4. In ABC, AB = 8,BC = 10, and AC = 7
Order the angles of the triangle from smallest to largest.
a.
b.
C.
d.
Answer:
B, C, A
Step-by-step explanation:
If one side of a triangle is longer than a second side, then the angle opposite the first side is larger than the angle opposite the second side.
Draw the triangle.
AC (7) is opposite from B
AB (8) is opposite from C
BC (10) is opposite from A
From smallest to largest: 7>8>10
7, 8, 10
or
B, C, A
Will anyone help me with geometry ASAP!? Please!? In desperate help!!!
Answer:
14. C 41
15. k = 72
Step-by-step explanation:
14.
For parallel lines, alternate exterior angles must be congruent.
3x - 43 = 80
3x = 123
x = 41
15.
The sum of the measures of the angles of a triangle is 180 deg.
k + 33 + 75 = 180
k + 108 = 180
k = 72
Answer:
1. 32
2. 41
3. 72
Step-by-step explanation:
Factor the trinomial!! PLEASE HELP and if possible please explain how to do this!!
Answer:
d. a = 39
Step-by-step explanation:
Question:
for which value of "a" will the trinomial be factorizable.
x^2+ax-40
For the expression to have integer factors, a = sum of the pairs of factors of -40.
-40 has following pairs of factors
{(1,-40), (2,-20, (4,-10), (5,-8), (8, -5), (10,-4), (20,-2), (40,-1) }
meaning that the possible values of a are
+/- 39, +/- 18, +/- 6, +/- 3
out of which only +39 appears on answer d. a=39
Suppose you just purchased a digital music player and have put 12 tracks on it. After listening to them you decide that you like 2 of the songs. With the random feature on your player, each of the 12 songs is played once in random order. Find the probability that among the first two songs played (a) You like both of them. Would this be unusual? (b) You like neither of them. (c) You like exactly one of them. (d) Redo (a)-(c) if a song can be replayed before all 12 songs are played.
Answer:
The answer is below
Step-by-step explanation:
We have the following information:
Number of songs you like = 2
Total number of songs = 12
a) P(you like both of them) = 2/12 x 1/11 = 0.015
This is unusual because the probability of the event is less than 0.05
b) P(you like neither of them) = 10/12 x 9/11 = 0.68
c) P(you like exactly one of them) = 2 x 2/12 x 10/11 = 0.30
d) If a song can be replayed before all 12,
P(you like both of them) = 2/12 x 2/12 =0.027
This is unusual because the probability of the event is less than 0.05
P(you like neither of them) = 9/12 x 9/12 = 0.5625
P(you like exactly one of them) = 2 x 2/12 x 9/12 = 0.25
15% as a fraction in its lowest terms is:
-3/20
-5/100
-1/15
-3/100
Answer:
3/20
Step-by-step explanation:
15%
15/100
/5 /5
3/20
The probability of a randomly selected adult in one country being infected with a certain virus is 0.005. In tests for the virus, blood samples from 27 people are combined. What is the probability that the combined sample tests positive for the virus? Is it unlikely for such a combined sample to test positive? Note that the combined sample tests positive if at least one person has the virus.
Answer:
The probability is 12.66%.
This is a low probability, so it is unlikely for such a combined sample to test positive.
Step-by-step explanation:
If the probability of being infected is 0.005, the probability of not being infected is 0.995.
Then, to find the probability of at least one of the 27 people being infected P(A), we can find the complementary case: all people are not infected: P(A').
[tex]P(A') = 0.995^{27}[/tex]
[tex]P(A') = 0.8734[/tex]
Then we can find P(A) using:
[tex]P(A) + P(A') = 1[/tex]
[tex]P(A) = 1 - 0.8734[/tex]
[tex]P(A) = 0.1266 = 12.66\%[/tex]
This is a low probability, so it is unlikely for such a combined sample to test positive.
Which of the following graphs is described by the function given below?
y = 2x^2 + 8x + 3
Answer:
Option A
Step-by-step explanation:
Equation of the given quadratic function is,
y = 2x² + 8x + 3
y = 2(x² + 4x) + 3
= 2(x² + 4x + 4 - 4) + 3
= 2(x + 2)² - 8 + 3
= 2(x + 2)² - 5
By comparing this equation with the equation of a quadratic function in vertex form,
y = a(x - h)² + k
Here (h, k) is the vertex of the parabola
Vertex of the given equation will be (-2, -5) and coefficient 'a' is positive (a > 0)
Therefore, vertex will lie in the 3rd quadrant and the parabola will open upwards.
Option (A). Graph A will be the answer.
Two balls are drawn in succession out of a box containing 2 red and 5 white balls. Find the probability that at least 1 ball was red, given that the first ball was (Upper A )Replaced before the second draw. (Upper B )Not replaced before the second draw.
Answer:
With replacement = 14/49without replacement = 3/7Step-by-step explanation:
Since there are 2 red and 5 white balls in the box, the total number of balls in the bag = 2+5 = 7balls.
Probability that at least 1 ball was red, given that the first ball was replaced before the second can be calculated as shown;
Since at least 1 ball picked at random, was red, this means the selection can either be a red ball first then a white ball or two red balls.
Probability of selecting a red ball first then a white ball with replacement = (2/7*5/7) = 10/49
Probability of selecting two red balls with replacement = 2/7*2/7 = 4/49
The probability that at least 1 ball was red given that the first ball was replaced before the second draw= 10/49+4/49 = 14/49
If the balls were not replaced before the second draw
Probability of selecting a red ball first then a white ball without replacement = (2/7*5/6) = 10/42 = 5/21
Probability of selecting two red balls without replacement = 2/7*2/6 = 4/42 = 2/21
The probability that at least 1 ball was red given that the first ball was not replaced before the second draw = 5/21+4/21 = 9/21 = 3/7
The probability that at least 1 ball was red, given that the first ball was replaced before the second draw is 28.5%; and the probability that at least 1 ball was red, given that the first ball was not replaced before the second draw is 22.5%.
Since two balls are drawn in succession out of a box containing 2 red and 5 white balls, to find the probability that at least 1 ball was red, given that the first ball was A) replaced before the second draw; and B) not replaced before the second draw; the following calculations must be performed:
2 + 5 = X7 = X
(2/7 + 2/7) / 2 = X (0.285 + 0.285) / 2 = X 0.285 = X
(2/7 + 1/6) / 2 = X (0.28 + 0.16) / 2 = X 0.451 / 2 = X 0.225 = X
Therefore, the probability that at least 1 ball was red, given that the first ball was replaced before the second draw is 28.5%; and the probability that at least 1 ball was red, given that the first ball was not replaced before the second draw is 22.5%.
Learn more about probability in https://brainly.com/question/14393430
how many are 4 x 4 ?
16, think of 4 plus 4 plus 4 plus 4.
Which set of numbers can represent the lengths of the sides of a triangle? A. {1,2,3} B. {3,5,7} C. {3,9,14} D. {4,4,8}
The set of numbers that can represent the lengths of the sides of a triangle are 3,5,7. That is option B.
What is a triangle?Triangle is defined as a type of polygon that has three sides in which the sum of both sides is greater than the third side.
That is to say, 3+5 = 8 is greater than the third side which is 7.
Therefore, the set of numbers the would represent a triangle are 3,5,7.
Learn more about triangle here:
https://brainly.com/question/17335144
#SPJ1
Select the correct answer.
If two angles of a triangle have equal measures and the third angle measures 90º, what are the angle measures of the triangle?
ОА.
60°, 60°, 60°
OB.
459,909, 90°
Ос.
30°, 30°, 90°
OD.
45°, 45°, 90°
Answer:
OD. 45,45,90
Step-by-step explanation:
A common inhabitant of human intestines is the bacterium Escherichia coli. A cell of this bacterium in a nutrient-broth medium divides into two cells every 20 minutes. The initial population of a culture is 58 cells. (a) Find the relative growth rate. (Assume t is measured in hours.) k = (b) Find an expression for the number of cells after t hours. P(t) = (c) Find the number of cells after 8 hours. cells (d) Find the rate of growth after 8 hours. (Round your answer to three decimal places.) billion cells per hour (e) When will the population reach 20,000 cells? (Round your answer to two decimal places.) hr
Answer:
a) k=2.08 1/hour
b) The exponential growth model can be written as:
[tex]P(t)=Ce^{kt}[/tex]
c) 977,435,644 cells
d) 2.033 billions cells per hour.
e) 2.81 hours.
Step-by-step explanation:
We have a model of exponential growth.
We know that the population duplicates every 20 minutes (t=0.33).
The initial population is P(t=0)=58.
The exponential growth model can be written as:
[tex]P(t)=Ce^{kt}[/tex]
For t=0, we have:
[tex]P(0)=Ce^0=C=58[/tex]
If we use the duplication time, we have:
[tex]P(t+0.33)=2P(t)\\\\58e^{k(t+0.33)}=2\cdot58e^{kt}\\\\e^{0.33k}=2\\\\0.33k=ln(2)\\\\k=ln(2)/0.33=2.08[/tex]
Then, we have the model as:
[tex]P(t)=58e^{2.08t}[/tex]
The relative growth rate (RGR) is defined, if P is the population and t the time, as:
[tex]RGR=\dfrac{1}{P}\dfrac{dP}{dt}=k[/tex]
In this case, the RGR is k=2.08 1/h.
After 8 hours, we will have:
[tex]P(8)=58e^{2.08\cdot8}=58e^{16.64}=58\cdot 16,852,338= 977,435,644[/tex]
The rate of growth can be calculated as dP/dt and is:
[tex]dP/dt=58[2.08\cdot e^{2.08t}]=120.64e^2.08t=2.08P(t)[/tex]
For t=8, the rate of growth is:
[tex]dP/dt(8)=2.08P(8)=2.08\cdot 977,435,644 = 2,033,066,140[/tex]
(2.033 billions cells per hour).
We can calculate when the population will reach 20,000 cells as:
[tex]P(t)=20,000\\\\58e^{2.08t}=20,000\\\\e^{2.08t}=20,000/58\approx344.827\\\\2.08t=ln(344.827)\approx5.843\\\\t=5.843/2.08\approx2.81[/tex]
At her favorite sneakers store Nyeema saved $48 because of a
sale.
If the sneakers normally cost $120. How much did she save?
Answer:
40%
Step-by-step explanation:
We can find what percent 48 is of 120 by dividing:
48/120 = 0.4 or 40%
So, she saved 40% from the original price.