Answer:
0.2209 = 22.09% probability that in a randomly selected office hour, the number of student arrivals is 3.
Step-by-step explanation:
We have the mean during an interval, so the Poisson distribution is used.
Poisson distribution:
In a Poisson distribution, the probability that X represents the number of successes of a random variable is given by the following formula:
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
In which
x is the number of sucesses
e = 2.71828 is the Euler number
[tex]\mu[/tex] is the mean in the given interval.
A statistics professor finds that when she schedules an office hour for student help, an average of 3.3 students arrive.
This means that [tex]\mu = 3.3[/tex]
Find the probability that in a randomly selected office hour, the number of student arrivals is 3.
This is P(X = 3). So
[tex]P(X = x) = \frac{e^{-\mu}*\mu^{x}}{(x)!}[/tex]
[tex]P(X = 3) = \frac{e^{-3.3}*3.3^{3}}{(3)!} = 0.2209[/tex]
0.2209 = 22.09% probability that in a randomly selected office hour, the number of student arrivals is 3.
2. Commission: A car saleswoman earns a
commission of 7% on each car she sells. How
much did she earn on the sale of a car for
$12,500?
Answer:
Step-by-step explanation:
commission = 0.7% of $12,500
= 0.007×$12,500
= $87.5
A bacteria culture initially contains 100 cells and grows at a rate proportional to its size. After an hour the population has increased to 310.
(a) Find an expression for the number of bacteria after
hours.
(b) Find the number of bacteria after 3 hours.
(c) Find the rate of growth after 3 hours.
(d) When will the population reach 10,000?
Answer:
a) The expression for the number of bacteria is [tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex].
b) There are 2975 bacteria after 3 hours.
c) The rate of growth after 3 hours is about 3365.3 bacteria per hour.
d) A population of 10,000 will be reached after 4.072 hours.
Step-by-step explanation:
a) The population growth of the bacteria culture is described by this ordinary differential equation:
[tex]\frac{dP}{dt} = k\cdot P[/tex] (1)
Where:
[tex]k[/tex] - Rate of proportionality, in [tex]\frac{1}{h}[/tex].
[tex]P[/tex] - Population of the bacteria culture, no unit.
[tex]t[/tex] - Time, in hours.
The solution of this differential equation is:
[tex]P(t) = P_{o}\cdot e^{k\cdot t}[/tex] (2)
Where:
[tex]P_{o}[/tex] - Initial population, no unit.
[tex]P(t)[/tex] - Current population, no unit.
If we know that [tex]P_{o} = 100[/tex], [tex]t = 1\,h[/tex] and [tex]P(t) = 310[/tex], then the rate of proportionality is:
[tex]P(t) = P_{o}\cdot e^{k\cdot t}[/tex]
[tex]\frac{P(t)}{P_{o}} = e^{k\cdot t}[/tex]
[tex]k\cdot t = \ln \frac{P(t)}{P_{o}}[/tex]
[tex]k = \frac{1}{t}\cdot \ln \frac{P(t)}{P_{o}}[/tex]
[tex]k = \frac{1}{1}\cdot \ln \frac{310}{100}[/tex]
[tex]k\approx 1.131\,\frac{1}{h}[/tex]
Hence, the expression for the number of bacteria is [tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex].
b) If we know that [tex]t = 3\,h[/tex], then the number of bacteria is:
[tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex]
[tex]P(3) = 100\cdot e^{1.131\cdot (3)}[/tex]
[tex]P(3) \approx 2975.508[/tex]
There are 2975 bacteria after 3 hours.
c) The rate of growth of the population is represented by (1):
[tex]\frac{dP}{dt} = k\cdot P[/tex]
If we know that [tex]k\approx 1.131\,\frac{1}{h}[/tex] and [tex]P \approx 2975.508[/tex], then the rate of growth after 3 hours:
[tex]\frac{dP}{dt} = \left(1.131\,\frac{1}{h} \right)\cdot (2975.508)[/tex]
[tex]\frac{dP}{dt} = 3365.3\,\frac{1}{h}[/tex]
The rate of growth after 3 hours is about 3365.3 bacteria per hour.
d) If we know that [tex]P(t) = 10000[/tex], then the time associated with the size of the bacteria culture is:
[tex]P(t) = 100\cdot e^{1.131\cdot t}[/tex]
[tex]10000 = 100\cdot e^{1.131\cdot t}[/tex]
[tex]100 = e^{1.131\cdot t}[/tex]
[tex]\ln 100 = 1.131\cdot t[/tex]
[tex]t = \frac{\ln 100}{1.131}[/tex]
[tex]t \approx 4.072\,h[/tex]
A population of 10,000 will be reached after 4.072 hours.
find (f o g)(x)
f(x) = 5x+1, g(x)= *square root of x*
Step-by-step explanation:
Hey there!
Here;
f(x) = 5x + 1
g(x) = (√x)
Now;
fog(X) = f(g(x))
= f(√x)
= 5√x + 1
Therefore, fog(X) = 5√x + 1.
Hope it helps!
Plz do this, I’m so exhausted. Thxx
Answer:
12) B --> x < 8/3
13) B --> x ≤ 1/6
Step-by-step explanation:
12) Solving inequalities is just like solving normal equations where you and add, subtract, multiply and divide sides by the same value. Keep in mind dividing or multiplying by a negative flips the sign:
x - 10 < 6 - 5x
Add 5x to both sides to combine the x terms:
x - 10 < 6 - 5x
+5x +5x
6x - 10 < 6
Add 10 to both sides to isolate the x term:
6x - 10 < 6
+10 +10
6x < 16
Now, divide by 6 on both sides:
x < 8/3, this is B
13) Simplify 2 - 4:
2-3(2x + 1) ≤ 6x(-2)
Distribute:
2 - 6x - 3 ≤ -12x
Add 12x to both sides and combine like terms:
6x - 1 ≤ 0
Add 1 to both sides:
6x ≤ 1
Divide by 6:
x ≤ 1/6, this is B
Consider the functions z = 4 e^x ln y, x = ln (u cos v), and y = u sin v.
Express dz/du and dz/dv as functions of u and y both by using the Chain Rule and by expressing z directly in terms of u and v before differentiating.
Answer:
remember the chain rule:
h(x) = f(g(x))
h'(x) = f'(g(x))*g'(x)
or:
dh/dx = (df/dg)*(dg/dx)
we know that:
z = 4*e^x*ln(y)
where:
y = u*sin(v)
x = ln(u*cos(v))
We want to find:
dz/du
because y and x are functions of u, we can write this as:
dz/du = (dz/dx)*(dx/du) + (dz/dy)*(dy/du)
where:
(dz/dx) = 4*e^x*ln(y)
(dz/dy) = 4*e^x*(1/y)
(dx/du) = 1/(u*cos(v))*cos(v) = 1/u
(dy/du) = sin(v)
Replacing all of these we get:
dz/du = (4*e^x*ln(y))*( 1/u) + 4*e^x*(1/y)*sin(v)
= 4*e^x*( ln(y)/u + sin(v)/y)
replacing x and y we get:
dz/du = 4*e^(ln (u cos v))*( ln(u sin v)/u + sin(v)/(u*sin(v))
dz/du = 4*(u*cos(v))*(ln(u*sin(v))/u + 1/u)
Now let's do the same for dz/dv
dz/dv = (dz/dx)*(dx/dv) + (dz/dy)*(dy/dv)
where:
(dz/dx) = 4*e^x*ln(y)
(dz/dy) = 4*e^x*(1/y)
(dx/dv) = 1/(cos(v))*-sin(v) = -tan(v)
(dy/dv) = u*cos(v)
then:
dz/dv = 4*e^x*[ -ln(y)*tan(v) + u*cos(v)/y]
replacing the values of x and y we get:
dz/dv = 4*e^(ln(u*cos(v)))*[ -ln(u*sin(v))*tan(v) + u*cos(v)/(u*sin(v))]
dz/dv = 4*(u*cos(v))*[ -ln(u*sin(v))*tan(v) + 1/tan(v)]
With the information that you gather from the summary tables, test the following (you can use excel when appropriate): Determine if there is sufficient evidence to conclude the average amount of births is over 5000 in the United States and territories at the 0.05 level of significance. Determine if there is sufficient evidence to conclude the average amount of deaths is equal to 6000 in the United States and territories at the 0.10 level of significance. Determine if there is sufficient evidence to conclude the average amount of marriages is greater or equal to 2500 in the United States and territories at the .05 level of significance. Determine if there is sufficient evidence to conclude the average amount of divorces is less than or equal to 4000 in the United States and territories at the 0.10 level of significance.
Answer:
Kindly check explanation
Step-by-step explanation:
A.)
H0 : μ = 5000
H0 : μ > 5000
xbar = 6671 ; s = 8185.21 ; n = 52 ; α = 0.05
The test statistic :
T = (xbar - μ) ÷ (s/√(n))
T = (6671 - 5000) ÷ (8185.21/√52)
T = 3.814
Pvalue from Test statistic : ; df = n - 1 = 52-1= 51
Pvalue at 3.814; 51 = 0.000185
Pvalue < α ; Reject H0 and conclude that average birth is greater than 5000
B)
H0 : μ = 6000
H0 : μ < 6000
xbar = 4187 ; s = 4386 ; n = 52 ; α = 0.01
The test statistic :
T = (xbar - μ) ÷ (s/√(n))
T = (4187 - 6000) ÷ (4386/√52)
T = - 2.981
Pvalue from Test statistic : ; df = n - 1 = 52-1= 51
Pvalue at - 2.981; 51 = 0.0022
Pvalue < α ; Reject H0 and conclude that average death is less than 6000
C.)
H0 : μ < 2500
H0 : μ ≥ 2500
xbar = 2744 ; s = 3134.41 ; n = 52 ; α = 0.05
The test statistic :
T = (xbar - μ) ÷ (s/√(n))
T = (2744 - 2500) ÷ (3134.41/√52)
T = 0.561
Pvalue from Test statistic : ; df = n - 1 = 52-1= 51
Pvalue at 0.561; 51 = 0.289
Pvalue > α ; Fail to Reject H0 and conclude that average marriage is not greater Tha or equal to 2500
D.)
H0 : μ = 4000
H0 : μ ≤ 4000
xbar = 1451 ; s = 1217 ; n = 52 ; α = 0.01
The test statistic :
T = (xbar - μ) ÷ (s/√(n))
T = (1451 - 4000) ÷ (1217/√52)
T = - 15.10
Pvalue from Test statistic : ; df = n - 1 = 52-1= 51
Pvalue at - 15.10; 51 = 0.000001
Pvalue < α ; Reject H0 and conclude that average divorce is less eqaul to 4000
Find out the quotient
-72 ÷ (-2) = ?
-72 ÷ 2 = ?
72 ÷ (-2) = ?
(Thank you to whoever helps me out )
Answer/Step-by-step explanation:
✔️-72 ÷ (-2)
The division of two negative numbers will give us a positive number. i.e. - ÷ - = +
Therefore:
-72 ÷ (-2) = 36
✔️-72 ÷ 2
The division of a negative number and a positive number will give us a negative number. i.e. - ÷ + = -
Therefore:
-72 ÷ 2 = -36
✔️72 ÷ (-2)
The division of a positive number and a negative number will give us a negative number. i.e. + ÷ - = -
Therefore:
72 ÷ (-2) = -36
What is the value of q?
2/5
2/14
Answer:
2√14 prob I'm not 100% sure
If there is an error in solving the equation below, then explain the error and in what step the error is in the equation. If no error, then just type “no error”
Answer:
To solve for x, you must multiply by the reciprocal.
In this case, multiply both sides by [tex]\frac{3}{2}[/tex] .
When doing this the result will be x = 3
3. A)Find the next number in the sequence.
$1,27, 9, 3, _1_
B) Is the sequence arithmetic, geometric, or neither?
Help me find this answer please
9514 1404 393
Answer:
1/3; geometric
Step-by-step explanation:
Apparently, your sequence is ...
81, 27, 9, 3, 1, ...
The differences between these numbers vary, but the ratio of each to the one before is a constant:
27/81 = 9/27 = 3/9 = 1/3
The sequence is geometric with a common ratio of 1/3. The next number in the sequence is (1)(1/3) = 1/3.
HELP ASAP I WILL GIVE BRAINLIST
Find the length of an arc of a circle with a 8-cm radius associated with a central angle of 240 degrees. Give your answer in exact and approximate form to the nearest hundredth. Show and explain your work
Answer:
33.51 cm
Step-by-step explanation:
240/360 = 2/3 (Arc length is 2/3 of the total circumference)
C = 2[tex]\pi[/tex]r ( Calculate the total circumference)
C = 2(8)[tex]\pi[/tex]
C = 50.265
2/3(50.265) (Take 2/3 of the circumference. times 2 divide by 3)
33.51
Use a calculator and leave the answer to C and then multiply and divide. You get a more precise answer.
The exact arc length is [tex]\frac{32\pi}{3}[/tex] radians.
The arc length in approximate form is 33.49 radians.
What is the formula for arc length?[tex]s = r\times \theta[/tex]
where r is the radius of the circle and [tex]\theta[/tex] is the central angle in radians.
How to convert angle from degrees to radians?Radians = Degrees ×[tex]\frac{\pi}{180^{\circ}}[/tex]
For given question,
We have been given a circle with a 8-cm radius associated with a central angle of 240 degrees.
[tex]r=8~cm,~\theta=240^{\circ}[/tex]
First we convert angle in radians.
[tex]\theta=240^{\circ}\\\\\theta=240^{\circ} \times \frac{\pi}{180^{\circ}}\\\\ \theta=\frac{4\pi}{3}[/tex]
Using the formula of the arc length,
[tex]s=8\times \frac{4\pi}{3} \\\\s=\frac{32\pi}{3}[/tex]
The exact answer of the arc length is [tex]s=\frac{32\pi}{3}[/tex]
Substitute the value of [tex]\pi = 3.14[/tex]
So, the arc length would be,
[tex]\Rightarrow s=\frac{32\times \pi}{3}\\\\\Rightarrow s=\frac{32\times 3.14}{3}\\\\\Rightarrow s=33.49[/tex]radians
Therefore, the exact arc length is [tex]\frac{32\pi}{3}[/tex] radians.
the arc length in approximate form is 33.49 radians.
Learn more about the arc length here:
https://brainly.com/question/16403495
#SPJ2
Use the graph to find the y-intercept and axis of symmetry
Answer: (a) and (d)
Step-by-step explanation:
From the graph, vertex is at
Graph is same about the point [tex]x=2[/tex] . Therefore, axis of symmetry is the line [tex]x=2[/tex]
Y intercept is the place where curve intersect the Y-axis that is [tex](0,2)[/tex]
Option (a) and (d) are correct.
Josephine left home traveling at 25 mph. One hour later her friend, Steve, leaves from the same place and travels the same road traveling at 50 mph. How many hours will it take Steve to catch up to Josephine?
Answer:
1 hour
Step-by-step explanation:
J = 50 mph by 2 hours
S = 50 mph by 1 hour
2-1 = 1
Pierre Martina is comparing the cost of credit to the cash price of an item. If Pierre makes a down payment of $70 and pays $34 a
month for 24 months, how much more will that amount be than the cash price of $695? (Input the amount as a positive value.)
Amount of difference
Answer:
$191
Step-by-step explanation:
Find how much she will be paying over the 24 months:
34(24)
= 816
Add the down payment to this:
816 + 70
= 886
Find the difference between this and 695:
886 - 695
= 191
So, the difference will be $191 more
this is so confusing can anyone help?
Answer:
C.
Step-by-step explanation:
For an angle to be supplementary to another angle, they must be equal to 180. Angles 6, 10, 13, and 9 are all supplementary to angle 16. Although there are more choices in different answers it wouldn't work with question, so C is the right answer.
Angle 16 is supplementary to angle 9 by the Same Side Interior Angles Theorem, which makes it supplementary to angle 10 by the Alternate Exterior Angles Theorem, which is also congruent to angle 13 by the Vertical Angles Theorem, which is also supplementary to angle 6 by the Alternate Exterior Angles Theorem.
an amount of R3000, Is invested to three years at simple interest rate and it earned R905 interest. determine the simple interest rate at which the money was invested
Answer:
Step-by-step explanation:
P=R3000.00
T=3 years
SI=R905
SI=P\times R\times T\\R905=R3000\times \frac{r}{100}\times 3SI=P×R×T
R905=R3000×
100
r
×3
R905=\frac{R9000r}{100}R905=
100
R9000r
R905=\frac{R905}{R90}R905=
R90
R905
r=\frac{R905}{R90.}r=
R90.
R905
r=10.06\%r=10.06%
Please help! I feel like I'm drowning :(
Answer:
1d = -3
2b = 2
2c = 1
3a = 3
3d = 4
Step-by-step explanation:
Polynomial 1: [tex]x^2-8x+15[/tex]
Multiply the leading coefficient, 1, and the last term, 15. You get: 15.
Then, list out the factors of 15 and the addends of -8 until you get two of numbers that are the same:
Factors of 15: -5 * -3
Addends of -8: -5 + -3
Replace the -8x with -5x - 3x:
[tex]x^2-5x-3x+15[/tex]
Put parentheses around the first 2 terms & last 2 terms and factor like so:
[tex](x^2-5x)-(3x+15)[/tex]
[tex]x(x-5)-3(x-5)[/tex]
[tex](x-5)(x-3)[/tex]
Looking at the answer (ax + b)(cx + d), d would correspond with -3.
Polynomial 2: [tex]2x^3-8x^2-24x[/tex]
First factor out the x:
[tex]x(2x^{2}-8x-24)[/tex]
Divide the polynomial inside by 2 and place the 2 outside with the x:
[tex]2x(x^2-4x-12)[/tex]
Then find the factors of 1*-12 and the addends of -4 and see which two numbers match:
Factors of -12: -6 * 2
Addends of -4: -6 + 2
Replace the -8x with -6x + 2x:
[tex]2x(x^2-6x+2x-12)[/tex]
Put parentheses around the first 2 terms & last 2 terms and factor like so:
[tex]2x((x^2-6x)+(2x-12))[/tex]
[tex]2x(x(x-6)+2(x-6))[/tex]
[tex]2x((x+2)(x-6))[/tex]
[tex]2x(x+2)(x-6)[/tex]
Looking at the answer (2x)(ax + b)(cx + d), b & c would correspond with 2 & 1.
Polynomial 3: [tex]6x^2+14x+4[/tex]
Divide the polynomial by 2:
[tex](2)(3x^2+7x+2)[/tex]
Find the factors of 3*2 and the addends of 7 and see which two numbers match:
Factors of 6: 6 * 1
Addends of 7: 6 + 1
Replace the 7x with 6x + x:
[tex](2)(3x^2+6x+x+2)[/tex]
Put parentheses around the first 2 terms & last 2 terms and factor like so:
[tex](2)((3x^2+6x)+(x+2))[/tex]
[tex](2)(3x(x+2)+(x+2))[/tex]
[tex](2)((3x+1)(x+2))[/tex]
[tex](2)(3x+1)(x+2)[/tex]
Then multiply the 2 with the (x+2) and here's your final answer:
[tex](3x+1)(2x+4))[/tex]
Looking at the answer (ax + b)(cx + d), a & d correspond with 3 & 4.
Hope that helps (●'◡'●)
(This took a while to write, sorry about that)
class 7th chapter: Simple Equation
The solution of the equation p-1 =20 is -------- *
a) 19
b) 20
c) 21
Answer:
C
Step-by-step explanation:
p=20+1
238.64 yards.what is the diameter of the field?use 3.14 for pie and do not round your answer
Answer:
It should be 8.6 yards, as 238.64÷3.14 = 74.
√74 = 8.60, or 8.6 :)
Amy needs to mail a gift card to a friend. She uses 47-cent stamps and 6-cent stamps to pay $2.42 in postage. How many of each stamp did Amy use?
Answer:
Answer:Amy used 4 41-cent stamps and 8 6-cent stamps.
Step-by-step explanation:
Let x represent the number of 41-cent stamps that Amy used. Let y represent the number of 6-cent stamps that Amy used.
41 cents = 41/100 = $0.41
6 cents = 6/100 = $0.06
She uses 41-cent stamps and 6-cent stamps to pay $2.12 in postage. It means that
0.41x + 0.06y = 2.12
Multiplying through by 100, it becomes
41x + 6y = 212
6y = 212 -41x
We would test for corresponding values of x and y that satisfies the equation and they must be whole numbers.
If x = 3,
6y = 212 - 41 × 3 = 89
y = 89/6 = 14.8333
If x = 4,
6y = 212 - 41 × 4 = 48
y = 48/6 = 8
Answer:Amy used 4 41-cent stamps and 8 6-cent stamps.
Step-by-step explanation:
Let x represent the number of 41-cent stamps that Amy used. Let y represent the number of 6-cent stamps that Amy used.
41 cents = 41/100 = $0.41
6 cents = 6/100 = $0.06
She uses 41-cent stamps and 6-cent stamps to pay $2.12 in postage. It means that
0.41x + 0.06y = 2.12
Multiplying through by 100, it becomes
41x + 6y = 212
6y = 212 -41x
We would test for corresponding values of x and y that satisfies the equation and they must be whole numbers.
If x = 3,
6y = 212 - 41 × 3 = 89
y = 89/6 = 14.8333
If x = 4,
6y = 212 - 41 × 4 = 48
y = 48/6 = 8
What is equal to 30- 6v - 13w
f(x) =x-4/x+5
and g(x) = 2x-1
Find the composition f•g
Step-by-step explanation:
2x-1 - (4/(2x-1)) + 5
2x^2 -4x -2 -4 + 10x - 5
2x^2 +6x -11
Identify the transformation that occurs to create the graph of h(x).
H(x)=f(x+3)
Answer: The graph moved left 3 units.
(x, y) = (x - 3, y)
Which option distinguishes what can be inferred in the following scenario?
Climatologists have recently observed a slow, steady increase in temperatures, which coincides with more frequent severe weather and higher sea levels.
1.The global climate is affected by human activity.
2.The global climate is undergoing significant changes.
3.The global climate is increasing concentrations of carbon dioxide.
4.The global climate is experiencing more severe weather because temperatures have increased.
The global climate is undergoing significant changes.
Alex thinks of a number. he squares it, then takes away five .Next multiplies it by 4 ,takes away seven, divides it by three ,and finally adds six his answer is nine what number did he start with
Answer:
3
Step-by-step explanation:
start with the ending answer and go backwards
Answer:
3.
Step-by-step explanation:
.
The function f is defined by f(x)=2x+5/x+4 find f (3x)
Answer:
[tex]\displaystyle f(3x) = \frac{6x + 5}{3x + 4}[/tex]
General Formulas and Concepts:
Algebra I
FunctionsFunction NotationStep-by-step explanation:
Step 1: Define
Identify
[tex]\displaystyle f(x) = \frac{2x + 5}{x + 4}[/tex]
Step 2: Find
Substitute in x [Function f(x)]: [tex]\displaystyle f(3x) = \frac{2(3x) + 5}{3x + 4}[/tex]Simplify: [tex]\displaystyle f(3x) = \frac{6x + 5}{3x + 4}[/tex]Plz help. Last one today. 20 points. Thx!
Hello friends!
Can anyone of you solve this?
so please solve
Step-by-step explanation:
each point should be at a 2. the center is 0,0
Identify the domain of the function shown in the graph.
What is the sum of 4th squared number and the 2nd cube number
Answer:
mark me as brinalist if answers are correct