Answer:
a) P(0) = 80
b) [tex]P(t) = 80(2.2361)^t[/tex]
c) 22,363 cells.
d) The rate of growth after 7 hours is of 18,000 bacteria per hour.
e) 9.7 hours.
Step-by-step explanation:
A bacteria culture grows with a constant relative growth rate.
This means that the population is given by:
[tex]P(t) = P(0)(1+r)^t[/tex]
In which P(0) is the initial population and r is the growth rate, as a decimal.
After 2 hours there are 400 bacteria and after 8 hours the count is 50,000.
This means that in 6 hours, the population went from 400 bacteria to 50,000 bacteria. We use this to find r. So
[tex]50000 = 400(1+r)^6[/tex]
[tex](1+r)^6 = \frac{50000}{400}[/tex]
[tex](1+r)^6 = 125[/tex]
[tex]\sqrt[6]{(1+r)^6} = \sqrt[6]{125}[/tex]
[tex]1 + r = 125^{\frac{1}{6}}[/tex]
[tex]1 + r = 2.2361[/tex]
So
[tex]P(t) = P(0)(2.2361)^t[/tex]
(a) Find the initial population. P(0)
We have that P(2) = 400. We use this to find P(0). So
[tex]P(t) = P(0)(2.2361)^t[/tex]
[tex]400 = P(0)(2.2361)^2[/tex]
[tex]P(0) = \frac{400}{(2.2361)^2}[/tex]
[tex]P(0) = 80[/tex]
So
[tex]P(t) = 80(2.2361)^t[/tex]
(b) Find an expression for the population after t hours.
[tex]P(t) = 80(2.2361)^t[/tex]
(c) Find the number of cells after 7 hours.
This is P(7). So
[tex]P(7) = 80(2.2361)^7 = 22363[/tex]
22,363 cells.
(d) Find the rate of growth after 7 hours.
We have to find the derivative when t = 7. So
[tex]P(t) = 80(2.2361)^t[/tex]
[tex]P^{\prime}(t) = 80\ln{2.2361}(2.2361)^t[/tex]
[tex]P^{\prime}(7) = 80\ln{2.2361}(2.2361)^7 = 18000[/tex]
The rate of growth after 7 hours is of 18,000 bacteria per hour.
(e) When will the population reach 200,000?
This is t for which [tex]P(t) = 200000[/tex]. So
[tex]P(t) = 80(2.2361)^t[/tex]
[tex]200000 = 80(2.2361)^t[/tex]
[tex](2.2361)^t = \frac{200000}{80}[/tex]
[tex](2.2361)^t = 2500[/tex]
[tex]\log{(2.2361)^t} = \log{2500}[/tex]
[tex]t\log{2.2361} = \log{2500}[/tex]
[tex]t = \frac{\log{2500}}{\log{2.2361}}[/tex]
[tex]t = 9.7[/tex]
So 9.7 hours.
Help please!!!! Im really stuck.
Answer: 275 adults and 130 children
Step-by-step explanation:
First, find the value of one variable by rearranging a equation:
[tex]a+c=405\\c=405-a[/tex]
Substitute it into the other equation and solve for a:
[tex]12a+5c=3950\\12a+5(405-a)=3950\\12a+2025-5a=3950\\12a-5a=3950-2025\\7a=1925\\a=\frac{1925}{7} =275[/tex]
Use the a-value to find b by substituting it into the rearranged equation:
[tex]c=405-a=405-275=130[/tex]
Therefore, the answer would be:
[tex]\left \{ {{a=275} \atop {c=130}} \right.[/tex]
the perimeter of a rectangular field is 346 yards if the length of the field is 95 yards whay is its width
Answer:
78 yards
Step-by-step explanation:
The perimeter of a rectangle is given by
P = 2(l+w)
346 = 2(95+w)
Divide each side by 2
346/2 = 2/2(95+w)
173 = 95+w
Subtract 95 from each side
173-95 = 95+w-95
78 = w
CAN SOMEONE PLEASE HELL ME WITH THIS PROBLEM? THANK YOU!!!
Answer:
71
Step-by-step explanation:
The reference angle is always the smallest angle with the x-axis.
The nearest x axis is at 0 or another name for 0 is 360
360 -289 = 71
The reference angle is 71
Please show your work this question what made you come to the conclusion. Thank you
Answer:
B the range, the x- and y-intercept
Step-by-step explanation:
the domain stays the same : all values of x are possible out of the interval (-infinity, +infinity).
but the range changes, as for the original function y could only have positive values - even for negative x.
the new function has a first term (with b) that can get very small for negative x, and then a subtraction of 2 makes the result negative.
the y-intercept (x=0) of the original function is simply y=1, as b⁰=1.
the y-intercept of the new function is definitely different, because the first term 3×(b¹) is larger than 3, because b is larger than 1. and a subtraction of 2 leads to a result larger than 1, which is different to 1.
the original function has no x-intercept (y=0), as this would happen only for x = -infinity. and that is not a valid value.
the new function has an x-intercept, because the y-values (range) go from negative to positive numbers. any continuous function like this must therefore have an x-intercept (again, y = the function result = 0)
[tex] 3 {b}^{x + 1} = 2[/tex]
[tex] {b}^{x + 1} = 2 \div 3[/tex]
[tex] log_{b}(2 \div 3) = x + 1[/tex]
[tex]x = log_{b}(2 \div 3) - 1[/tex]
A student-faculty committee consisting of 6 members is to be chosen from a pool of candidates consisting of 5 students and 7 faculty members. The committee must have at least 2 student members and at least 1 faculty member. How many possibilities are there
Answer:
[tex]T=812[/tex]
Step-by-step explanation:
From the question we are told that:
No. Committee Members [tex]n=6[/tex]
Pool of : 5 students and 7 faculty members
At least 2 student members and at least 1 faculty member
Generally the committee is mathematically given by
The Total Events are
[tex]T=(^5C_2*^7C_4)+(^5C_3)*(^7C_3)+(^5C_4)*(^7C_2)+(^5C_5)*(^7C_1)[/tex]
[tex]T=350+350+105+7[/tex]
[tex]T=812[/tex]
This is a list of the heights ( each nearest cm ) of 12 children
150 134 136 139 131 141
132 134 136 137 150 146
Select the type of the data.PLEASE HELP CHOOSE ONE
Discrete
Continuous
Categorical
Qualitative
Answer:
qualitative
Step-by-step explanation:
bcos it is in quality format
did from six times a certain number the result is 96 what is the number
Answer:
The number is 16
Step-by-step explanation:
Number : x
Procedure and resolution:
6x = 96
x = 96/6
x = 16
Good Luck!If r = 0.97, this indicates a ________ correlation. Question 10 options: A) weak negative B) weak positive C) strong negative D) strong positive
Answer:C
Step-by-step explanation:
A correlation of -0.97 is a strong negative correlation while a correlation of 0.10 would be a weak positive correlation
Answer:
C) strong negative.
Step-by-step explanation:
If 3(nP2 + 24)=2nP2, find the positive value of n
Answer:
[tex]n = 8[/tex]
Step-by-step explanation:
Given
[tex]3(^nP_2 + 24) = ^{2n}P_2[/tex]
Required
Find n
To do this, we simply apply permutations formula
[tex]nP_r = \frac{n!}{(n -r)!}[/tex]
So, we have:
[tex]3 * [\frac{n!}{(n -2)!} + 24] = \frac{2n!}{(2n -2)!}[/tex]
Expand
[tex]3 * [\frac{n * (n - 1) * (n - 2)!}{(n -2)!} + 24] = \frac{2n * (2n - 1) * (2n - 2)}{2n - 2}[/tex]
[tex]3 * [n * (n - 1) + 24] = 2n * (2n - 1)[/tex]
[tex]3 * [n^2 - n + 24] = 4n^2 - 2n[/tex]
Open bracket
[tex]3n^2 - 3n + 72 = 4n^2 - 2n[/tex]
Collect like terms
[tex]3n^2 - 4n^2- 3n+2n + 72 = 0[/tex]
[tex]-n^2- n + 72 = 0[/tex]
Expand
[tex]-n^2 -9n + 8n + 72 = 0[/tex]
Factorize
[tex]-n(n +9) - 8(n + 9) = 0[/tex]
Factor out n + 9
[tex](-n -8)(n + 9) = 0[/tex]
Split
[tex](-n -8)= 0 \ or\ (n + 9) = 0[/tex]
Solve for n
[tex]n =8\ or\ n = -9[/tex]
The positive value is [tex]n = 8[/tex]
A ladder leans against the side of the a house. The ladder is 19 feet long and forms an angle of elevation of 75 degree when leaned against the house. How far away from the house is the ladder? Round your answer to the nearest tenth.
Answer: 18.35259
Hope it helps!
Can someone help please
( x - 2 )( x - 8 )( x + 5 ) =
( x^2 - 10x + 16 )( x + 5 ) =
x^3 - 10x^2 + 16x + 5x^2 - 50x + 80 =
x^3 + ( - 10 + 5 )x^2 + ( 16 - 50)x + 80 =
x^3 - 5x^2 - 34x + 80
A hexagonal pyramid is located ontop of a hexagonal prism. How many faces are there?
A. 15
B. 24
C. 6
D. 13
Answer:
15
Step-by-step explanation:
The figure has total 15 faces, the correct option is A.
What is a Hexagon?A hexagon is a polygon with six sides.
A hexagonal pyramid has 8 faces
From (2 hexagonal base + 6 lateral surfaces)
A hexagonal prism has 7 faces
From ( A hexagonal base + 6 lateral faces)
Total faces the figure has is 8 +7 = 15
To know more about Hexagon
https://brainly.com/question/3295271
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PLEASE ANSWER!!!!!!!
Graph the line with x - intercept of -2 and has a slope of 3
Answer:
The graph is given below.
Step-by-step explanation:
X intercept = - 2
slope, m = 3
The point t which the line intersects the X axis is (-2 , 0) .
The equation of line passing through a point and the slope is given
y - y' = m (x - x')
y - 0 = 3 (x + 2)
y = 3 x + 6
So, the graph is given below.
Compare by y = m x + c .
here y intercept is 6 .
A vending machine dispenses coffee into a twelve ounce cup he amount of coffee dispensed into the cup is normally distributed with a standard deviation of 0.006 ounce. You can allow the cup to overfill 4â% of the time. What amount should you set as the mean amount of coffee to beâ dispensed?
Answer:
this mean amount of coffee to be dispensed would be 11.99, approximately 12
Step-by-step explanation:
first of all we have this information available to answer this question.
standard deviation σ = 0.006 ounces
prob(x > 12) = 0.04
we use this formular to find the mean
z = x - μ/σ
the value of the z score at 4% is equal to 1.7507
such that
[tex]1.7507 = \frac{12-u}{0.006}[/tex]
we cross multiply from this stage
1.7507*0.006 = 12-μ
0.0105042 = 12-μ
μ = 12 - 0.0105042
herefore, the mean amount μ = 11.99 this can be approximated to 12
An isosceles right triangle has a hypotenuse that measures 4√2 cm. What is the area of the triangle?
HELP
Answer:
8 cm^2
Step-by-step explanation:
If the triangle is isosceles the sides are the same
Let the sides be x
We know that we can use the Pythagorean theorem
a^2+b^2 = c^2 where a and b are the sides and c is the hypotenuse
x^2+x^2 = (4 sqrt(2))^2
2x^2 =16(2)
2x^2 = 32
Divide by 2
2x^2/ 32/2
x^2 = 16
Taking the square root of each side
sqrt(x^2) = sqrt(16)
x = 4
The area of the triangle is
A =1/2 bh
A = 1/2 (4) (4)
A = 1/2(16)
A = 8
Answer:
8
Step-by-step explanation:
a^2 + b^2 = c^2
c = [tex]4\sqrt{2}[/tex]
[tex]c^{2} = 32[/tex]
a^2 + b^2 = 32
a=b (isosceles triangle)
a=b=4
base = 4
height = 4
area = 1/2 bh = 1/2(4)(4) = 8
The mathematics department of a college has 6 male professors, 12 female professors, 14 male teaching assistants, and 11 female teaching assistants. If a person is selected at random from the group, find the probability that the selected person is a teaching assistant or a female.
The probability is ___.
(Type an integer or a fraction. Simplify your answer.)
Answer:
37/43
Step-by-step explanation:
6+12+14+11=43
Males: 6+14=20
Females: 11+12=23
If the selected person is a teaching assistant or a female, then the probability is 11+12+14=37. 37/43
6 less than six times a number is 42 what is the number
Answer:
x = 8
General Formulas and Concepts:
Pre-Algebra
Equality Properties
Multiplication Property of Equality Division Property of Equality Addition Property of Equality Subtraction Property of EqualityStep-by-step explanation:
Step 1: Define
Identify
6x - 6 = 42
Step 2: Solve for x
[Addition Property of Equality] Add 6 on both sides: 6x = 48[Division Property of Equality] Divide 6 on both sides: x = 8Answer: -6
Step-by-step explanation:
We can create an equation based on the info given.
6-6x=42 Now you solve for x, the unknown number.
-6 -6 Subtract 6 on both sides
-6x=36
/-6 /-6 Divide by -6 on both sides
x=-6
The number is -6.
If a seed is planted, it has a 90% chance of growing into a healthy plant.
If 6 seeds are planted, what is the probability that exactly 2 don't grow?
Answer:
[tex]\displaystyle\frac{19,683}{200,000}\text{ or }\approx 9.84\%[/tex]
Step-by-step explanation:
For each planted seed, there is a 90% chance that it grows into a healthy plant, which means that there is a [tex]100\%-90\%=10\%[/tex] chance it does not grow into a healthy plant.
Since we are planting 6 seeds, we want to choose 2 that do not grow and 4 that do grow:
[tex]\displaystyle \frac{1}{10}\cdot \frac{1}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}[/tex]
However, this is only one case that meets the conditions. We can choose any 2 out of the 6 seeds to be the ones that don't grow into a healthy plant, not just the first and second ones. Therefore, we need to multiply this by number of ways we can choose 2 things from 6 (6 choose 2):
[tex]\displaystyle \binom{6}{2}=\frac{6\cdot 5}{2!}=\frac{30}{2}=15[/tex]
Therefore, we have:
[tex]\displaystyle\\P(\text{exactly 2 don't grow})=\frac{1}{10}\cdot \frac{1}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \binom{6}{2},\\\\P(\text{exactly 2 don't grow})=\frac{1}{10}\cdot \frac{1}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot 15,\\\\P(\text{exactly 2 don't grow})=\boxed{\frac{19,683}{200,000}}\approx 9.84\%[/tex]
Answer:
[tex] {?}^{?} However, this is only one case that meets the conditions. We can choose any 2 out of the 6 seeds to be the ones that don't grow into a healthy plant, not just the first and second ones. Therefore, we need to multiply this by number of ways we can choose 2 things from 6 (6 choose 2):
\displaystyle \binom{6}{2}=\frac{6\cdot 5}{2!}=\frac{30}{2}=15(26)=2!6⋅5=230=15
Therefore, we have:
\begin{gathered}\displaystyle\\P(\text{exactly 2 don't grow})=\frac{1}{10}\cdot \frac{1}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \binom{6}{2},\\\\P(\text{exactly 2 don't grow})=\frac{1}{10}\cdot \frac{1}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot \frac{9}{10}\cdot 15,\\\\P(\text{exactly 2 don't grow})=\boxed{\frac{19,683}{200,000}}\approx 9.84\%\end{gathered}P(exactly 2 don’t grow)=101⋅101⋅109⋅109⋅109⋅109⋅(26),P(exactly 2 don’t grow)=101⋅101⋅109⋅109⋅109⋅109⋅15,P(exactly 2 don’t grow)=200,00019,683≈9.84%
[/tex]
Find the missing side round your answer to the nearest tenth
Answer:
x=13.2
Step-by-step explanation:
cos(43)=x/18
x=18×cos(43)
x=13.2
Answered by GAUTHMATH
What is the domain of the function
v=m***
O x2
O
O O xe3
o
X> 3
ASAP
Answer:
The function will be exist if and only if :
[tex] \frac{ - x + 3}{2} > 0 \\ = > - x + 3 > 0 \\ = > - x > - 3 \\ = > x < 3 \\ \\ \therefore \bf \: domain \: \: \green{x < 3}[/tex]
Solve the system.
x-y =-1
x+z=-5
y-z=2
Answer:
x= -2
y= -1
z= -3
Step-by-step explanation:
x-y= -1 (1)
x+z= -5 (2)
y-z= 2 (3)
(1)+(3)==> x-z= 1 (4)
(4)+(2)==> 2x= -4 ==> x= -2
we replace x by its value in equation (2):
-2+z= -5 ==> z= -3
we replace z by its value in equation (3):
y-(-3)= 2 ==> y+3=2 ==> y= -1
exchange rate for rand is 7 for $1 how any dollars would u receive is u exchange 21 rand
Answer:
$3
Step-by-step explanation:
7 rands for $1
7×3=21
21 rands for $3
Answer:
$3
Step-by-step explanation:
7 rand = 1 dollar
Divide both sides by 7 rand.
1 = (1 dollar)/(7 rand)
Notice that the fraction (1 dollar)/(7 rand) equals 1, so multiplying by it will not change the amount, just the units.
21 rand * (1 dollar)/(7 rand) =
= 21/7 dollar
= 3 dollar = $3
investing $12,000 in a savings account at 6% annual interest compounded monthly will result in approximately how much money after five years? use formula A 0 P(1 + r/m) ^mt
Answer:
$16186.20
Step-by-step explanation:
Assuming that P represents the initial amount, A represents the end amount, r represents the annual interest rate, m represents the amount of times compounded per year, and t represents the amount of years, we can write this as
A = P(1+r/m)^(mt)
Since 12,000 is invested, that is the initial amount. To find the interest rate as a decimal from a percent (as we need it in decimal form for this formula), we can divide the percent by 100 to get 6%/100 = 0.06 as our interest rate. Because there are 12 months in a year, the interest is compounded 12 times a year, and since it takes 5 years, t=5. Our formula is now
A = 12000 * (1+0.06/12)^(12 * 5)
A = 12000 * (1+0.06/12) ^(60)
A = 16186.20 rounded to the nearest cent
Of all the people applying for a certain job 75% are qualified and 25% are not. The personnel manager claims that she approves qualified people 80% of the time, she approves unqualified people 30% of the time. Find the probability that a person is qualified if he or she was approved by the manager The probability is:_______.
Type an integer or decimal rounded to four decimal places as needed)
Answer:
The probability is: 0.8889.
Step-by-step explanation:
Conditional Probability
We use the conditional probability formula to solve this question. It is
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)}[/tex]
In which
P(B|A) is the probability of event B happening, given that A happened.
[tex]P(A \cap B)[/tex] is the probability of both A and B happening.
P(A) is the probability of A happening.
In this question:
Event A: Approved
Event B: Qualified
Probability of a person being approved:
80% of 75%(qualified)
30% of 25%(not qualified). So
[tex]P(A) = 0.8*0.75 + 0.3*0.25 = 0.675[/tex]
Probability of a person being approved and being qualified:
80% of 75%, so:
[tex]P(A \cap B) = 0.8*0.75[/tex]
Find the probability that a person is qualified if he or she was approved by the manager.
[tex]P(B|A) = \frac{P(A \cap B)}{P(A)} = \frac{0.8*0.75}{0.675} = 0.8889[/tex]
The probability is: 0.8889.
Suppose that the distribution of snake lengths in a certain park is not assumed to be symmetric. According to Chebyshev's Theorem, at least what percentage of snake lengths are within k =2.9 standard deviations of the mean?
According to Chebyshev,
P(|X - µ| ≤ 2.9σ) ≥ 1 - 1/2.9² ≈ 0.8811
find the missing length indicated
Answer:
192
Step-by-step explanation:
geometric mean theorem :
with p and q being the segments of the Hypotenuse, then
h = x = sqrt(p×q)
p = 144
q = 400-144 = 256
h = x = sqrt(144×256) = 12×16 = 192
A manufacturer of industrial solvent guarantees its customers that each drum of solvent they ship out contains at least 100 lbs of solvent. Suppose the amount of solvent in each drum is normally distributed with a mean of 101.8 pounds and a standard deviation of 3.76 pounds.
Required:
a. What is the probability that a drum meets the guarantee? Give your answer to four decimal places.
b. What would the standard deviation need to be so that the probability a drum meets the guarantee is 0.99?
Answer:
The answer is "0.6368 and 0.773".
Step-by-step explanation:
The manufacturer of organic compounds guarantees that its clients have at least 100 lbs. of solvent in every fluid drum they deliver. [tex]X\ is\ N(101.8, 3.76)\\\\P(X>100) =P(Z> \frac{100-101.8}{3.76}=P(Z>-0.47))[/tex]
For point a:
Therefore the Probability =0.6368
For point b:
[tex]P(Z\geq \frac{100-101.8}{\sigma})=0.99\\\\P(Z\geq \frac{-1.8}{\sigma})=0.99\\\\1-P(Z< \frac{-1.8}{\sigma})=0.99\\\\P(Z< \frac{-1.8}{\sigma})=0.01\\\\z-value =0.01\\\\area=-2.33\\\\ \frac{-1.8}{\sigma}=-2.33\\\\ \sigma= \frac{-1.8}{-2.33}=0.773[/tex]
If y = sin 3x, find y" in terms of y.
Answer:
-0.54
Step-by-step explanation:
Hope it helped.
• • •
Find the length of the side CD in the pentagon ABCDE.
A)
4√2 units
B)
12 units
C)
4 units
D)
4√10 units
Answer: A) 4√2 units
Step-by-step explanation:
Use the distance formula to find the distance(d) between Point D and Point C:
[tex]d=\sqrt{(x_{2}-x_{1})^{2}+(y_{2}-y_{1})^{2}}[/tex]
Point D = (x₁, y₁) = (4, -2)Point C = (x₂, y₂) = (8, 2)[tex]d=\sqrt{(8-4)^{2}+(2-(-2))^{2}}=\sqrt{(4)^{2}+(4)^{2}}=\sqrt{16+16} =\sqrt{32} =4\sqrt{2}[/tex]
What is the domain of the following function?
Answer:
the domain is all real numbers except x=3
Step-by-step explanation:
The domain is the values that x can take
X can be all real number except when the denominators equal zero
x-3 ≠ 0
x≠3
the domain is all real numbers except 3