The difference between the cost and revenue functions is the profit function.
The retailer will start making money after 3 days.
Given that:
\(R(x) = 3x^3\:-\:21x^2\:+\:21x\:+\:45\)
\(A(x) = x^2 - 2x - 3\)
The retailer will start making money when R(x) > 0 i.e. when the profit is greater than 0.
So, we have:
\(3x^3 - 21x^2 + 21x + 45 > 0\)
Factor out 3
\(3(x^3 - 7x^2 +7x + 15) > 0\)
Divide through by 3
\(x^3 - 7x^2 +7x + 15 > 0\)
Expand
\(x^3 - 8x^2 + 15x + x^2 - 8x + 15 > 0\)
Further expand
\(x^3 - 5x^2 - 3x^2 + 15x + x^2 - 5x - 3x + 15 > 0\)
Factorize
\(x^2(x - 5) - 3x(x - 5) + x(x - 5) - 3(x -5) > 0\)
Factor out the common factors
\((x^2 - 3x)(x - 5) + (x - 3)(x - 5) > 0\)
Factor out x
\(x(x - 3)(x - 5) + (x - 3)(x - 5) > 0\)
Factor out (x - 3)(x - 5)
\((x - 3)(x - 5)(x + 1) > 0\)
Split
\(x - 3> 0\) or \(x - 5> 0\) or \(x + 1 > 0\)
Solve for x
\(x > 3\) or \(x > 5\) or \(x > -1\)
x cannot be negative.So:
\(x > 3\) or \(x > 5\)
Because 3 is less than 5, then the reasonable solution to the set is:
\(x > 3\)
Hence, the retailer will start making money after 3 days.
Read more about profit, cost and revenue functions at:
https://brainly.com/question/17164893
Can someone help me with this I do not know where to start.
Answer:
Try and start at the line?
Step-by-step explanation:
Many roads are shaped with a parabolic profile, in order to shed rainwater. The height, H, in inches of a new road that is being built through a swamp is given by H=−(12x−2)2+4
, where x is the width of the road in yards. The edges of the road are level with the surroundings so that H = 0. What is the width of the new road?
The width of the new road x = 1/3 yards.
Since the road is a parabola with H = -(12x - 2)² + 4 represents the height of the road over the swamp. The width of the new road is gotten when H = 0.
Solving the equationSo, H = -(12x - 2)² + 4
0 = -(12x - 2)² + 4
-(12x - 2)² + 4 = 0
Expanding the bracket, we have
-(144x² - 48x + 4) + 4 = 0
-144x² + 48x - 4 + 4 = 0
-144x² + 48x + 0 = 0
-144x² + 48x = 0
144x² - 48x = 0
Finding the value of xFactorizing, we have
48x(3x - 1) = 0
48x = 0 or 3x - 1 = 0
x = 0 or 3x = 1
x = 0 or x = 1/3
So, the width of the new road x = 1/3 yards.
Learn more about parabola here:
https://brainly.com/question/13947192
help will give brainiest
A recursive arithmetic sequence a₁ = -4 and aₙ = aₙ₋₁ + 11,
a) the value of a₁ = -4
b) The value of d = 11
c) The iterative sequence of the arithmetic sequence is -4, 7, 18, 29, 40, 51, 62, 73, 84, 95...….
d) The value of a₁₀ is 95.
Arithmetic Sequence:
Arithmetic sequence terms refer the difference between consecutive terms is always the same.
Given,
Here we have the recursive arithmetic sequence a₁ = -4 and aₙ = aₙ₋₁ + 11.
And we need to find the following:
a) a₁
b) d
c) iterative sequence rule
d) a₁₀
While we looking into the given expression we have easily identified the value f a₁ is -4 and the value of common difference d is 11.
Now we have to find the iterative sequence, that is non other than the consecutive values of the arithmetic sequence,
it can be calculated as follows:
a₂ = a₂₋₁ + 11 = a₁ + 11 = -4 + 11 = 7
Similarly, the next value is calculated by adding 11 to its previous values,
So, the value of
a₃ = 7 + 11 = 18
a₄ = 18 + 11 = 29
a₅ = 29 + 11 = 40
a₆ = 40 + 11 = 51
a₇ = 51 + 11 = 62
a₈ = 62 + 11 = 73
a₉ = 73 + 11 = 84
a₁₀ = 84 + 11 = 95
Therefore, the iterative sequence is calculated by adding 11 to it and the sequence is -4, 7, 18, 29, 40, 51, 62, 73, 84, 95...…..
And the value of a₁₀ is 95.
To know more about Arithmetic sequence here.
https://brainly.com/question/10396151
#SPJ1
Un bloque rectangular de metal mide 5 x 8 x 10 cm, tiene una masa de 500 gr, calcula su densidad en gr/cm³
Tu respuesta
What are the vertex focus and directrix of the parabola with the equation 12y=x^2-6x+45.
Vertex , focus , and directrix of the given equation of parabola
12y = x² -6x +45 are as follow:
Vertex = ( 3, 3)
Focus = ( 3, 6)
Directrix is y =0.
As given in the question,
Given equation of the parabola is:
12y = x² -6x +45
Simplify the equation of parabola to get standard form:
12y = x² - 6x + 9 - 9 + 45
⇒ 12 y = ( x - 3 )² + 36
⇒ 12y - 36 = ( x - 3 )²
⇒ 12( y - 3 ) = ( x - 3 )²
⇒ ( x - 3 )² = 4(3)(y - 3)
Standard form is :
( x - h )² = 4a ( y - k)
Here h = 3, k = 3 and a = 3
Vertex are ( h , k ) = ( 3, 3 )
Focus is ( h, k + a) = ( 3, 6)
Directrix is
y = k -p
⇒y = 3 - 3
⇒y = 0
Therefore, for the given parabola the vertex is (3,3) , focus is (3,6) and directrix is y = 0.
Learn more about parabola here
brainly.com/question/4074088
#SPJ4
if 2 square root 3 is a polynomial root, name another root of the polynomial, and explain how you know it must also be a root
2 + √3 is a polynomial root, then another root will be 2 - √3 for the polynomial .
For a given polynomial equation, where the degree of the equation is 1, it is said to be a quadratic equation. Since the given polynomial root is 2 + √3 ,the formula we refer to for calculating the solution of a quadratic formula is x = -b ± √(b² - 4ac) / 2a, which implies the roots be e [ -b + √(b² - 4ac) / 2a] and [ -b - √(b² - 4ac) / 2a].So, using the formula the root will be 2 - √3, here we can say that a complex root comes with conjugate pairs.
To know more about roots refer to the link https://brainly.com/question/1514617?referrer=searchResults.
#SPJ4
What is the area of this parallelogram? A = 31.2 ft^2 A = 35 ft^2 A = 47 1 / 2 ft² A = 662 ft^2
Answer:
C
Step-by-step explanation:
the area (A) of the parallelogram is calculated as
A = bh ( b is the base and h the perpendicular height )
here b = 9 \(\frac{1}{2}\) and h = 5 , then
A = 9 \(\frac{1}{2}\) × 5 = 47 \(\frac{1}{2}\) ft²
A small business earns a profit of $6500 in January and $17,500 in May. What is the rate of change in profit for this time period?
The rate of change in profit for this time period is per month.
A shipping container is in the form of a right rectangular prism, with dimensions of 30 ft by 8 ft by 7 ft 3 in. If the container holds 1096 cubic feet of shipped goods, what percent is empty?
As per the volume of a rectangular prism, it is found that 34.76% of the container is empty.
Volume of a rectangular prism
The volume of the rectangle prism is calculated by multiplying the length, breadth and height of the prism.
The formula for the volume of rectangle prism is
V = l x w x h
where
l represents the length
w represents the width
h represents the height
Given,
A shipping container is in the form of a right rectangular prism, with dimensions of 30 ft by 8 ft by 7 ft 3 in.
Here we need to find if the container holds 1096 cubic feet of shipped goods, what percent is empty
According to the given question,
Let us consider the length is 30ft, Width is 8ft and Height is 7ft.
Here the value 3ft refers the depth.
That one is also multiplied with the volume.
Therefore, the volume of the container is
=> 8 x 7 x 30
=> 1680
Therefore, the volume of the container is 1680 cubic feet.
So, here we have to percentage of the empty space for that we have to find the difference of them and convert it into percentage,
=> 1680 - 1096
=> 584
The percent of empty space is,
=> x% of 1680 = 584
=> x% = 584/1680
=> x% = 0.3476
=> x = 34.76
Therefore, 34.76% of rectangular prism container is empty.
To know more about Volume of rectangle prism here.
https://brainly.com/question/12702730
#SPJ1
Slope of line that passes through (2,7) and (-4,19)
To calculate the slope of the line, we have that its points are A(x₁, y₁) and B(x₂,y₂), we apply the following formula:
\(\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{m=\frac{\Delta y}{\Delta x} \iff m=\frac{y_2-y_1}{x_2-x_1} } \end{gathered}$}}\)
To solve, we have that the points are:
\(\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{A(x_1=\underbrace{2} \ \ , \ \ y_1=\overbrace{7} \ ) \ and \ B(x_2=\underbrace{-4} \ \ , \ \ y_2=\overbrace{19} } \end{gathered}$}}\)
What we do to solve is that we substitute this data in the formula provided above.
\(\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{m=\dfrac{y_2-y_1}{x_2-x_1} } \end{gathered}$}}\)
\(\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{m=\frac{19-7}{-4-2} } \end{gathered}$}}\)
\(\boxed{\large\displaystyle\text{$\begin{gathered}\sf \bf{m=\frac{12}{-6}=-2 } \end{gathered}$}}\)
The slope of the line that passes through (2,7) and (-4,19) is -2.there are 29.6 feet of carpet in a roll at the store. if it were cut into 8 equal pieces what would be the lenth of each peice
Answer:
Step-by-step explanation
First divide 29.6 by 8. Your answer will be 3.7.
the time to fly between new york city and chicago is uniformly distributed with a minimum of 96 minutes and a maximum of 100 minutes. what is the probability that a flight is between 97 and 98 minutes?
There is a 25% chance that a flight between New York City and Chicago will take between 97 and 98 minutes.
Since the time to fly between New York City and Chicago is uniformly distributed between 96 and 100 minutes, the probability of a flight being between any two times is proportional to the length of the time interval between those two times.
To find the probability that a flight is between 97 and 98 minutes, we need to calculate the length of the time interval between those two times, which is 1 minute.
Then, we divide the length of the interval by the length of the entire time range (100-96 = 4 minutes) to obtain the probability of a flight being between 97 and 98 minutes: Probability = 1 minute / 4 minutes = 0.25 or 25%.
Learn more about probability here:
https://brainly.com/question/30034780
#SPJ4
Answer this question!!!!!!!!!! plsss
Answer: $492.03
Step-by-Step explanation: just multiply 546.7*.10 and that equals 54.67
subtract 54.67 from 546.7
the total is now 492.03
a farmer plans to enclose a rectangular pasture adjacent to a river (see figure). the pasture must contain 245,000 square meters in order to provide enough grass for the herd. no fencing is needed along the river. what dimensions will require the least amount of fencing?
X = 700 m and Y = 350 m will require the least amount of fencing.
Area of a rectangular field = length × breath = 245000 = XY
⇒ Y = 245000/X
Perimeter of a rectangular field = X + 2Y
⇒P = X+ 2Y
⇒P = X + 490000/X
⇒ X + 490000X⁻¹
⇒P [X] = X + 490000X⁻¹
⇒P'[X] = 1+[-490000X⁻²]
⇒0 = 1 - 490000/X²
⇒X²= 490000
⇒X = 700 unit
As XY = 245000 [ area of a rectangle ]
⇒700Y = 245000
⇒Y = 350 unit.
Hence , P is minimum [ fencing ] when X = 700 unit and Y = 350 unit.
To understand more about maxima and minima refer -
https://brainly.com/question/27958412
#SPJ4
What is a possible result os simplifying the equation 15x-4=3(5x-4)?
Answer:
C. -4 = -12
Step-by-step explanation:
15x-4 = 3(5x-4)
15x - 4 = 15x - 12
-4 = -12
an example of a unti price youd find in germany-
given a=[55−2−5] and b=[−5−2−53] , use the frobenius inner product and the corresponding induced norm to determine the value of each of the following: [1-3] 21 (A,B) ||A|F 1 \BF 1 ВА,В radians.
Answer: Using the Frobenius inner product, we have:
(A,B) = a11b11 + a12b12 + a13b13 + a21b21 + a22b22 + a23b23 + a31b31 + a32b32 + a33b33
To find the corresponding induced norm, we first find the Frobenius norm of A:
||A||F = sqrt(|55|^2 + |-2|^2 + |-5|^2 + |-5|^2 + |-2|^2 + |-3|^2 + |1|^2 + |-3|^2 + |2|^2)
= sqrt(302)
Then, using the formula for the induced norm, we have:
||A|| = sup{||A||F * ||x|| / ||x||2 : x is not equal to 0}
= sup{sqrt(302) * sqrt(x12 + x22 + x32) / sqrt(x1^2 + x2^2 + x3^2) : x is not equal to 0}
Since we only need to find the value for A, we can let x = [1 0 0] and substitute into the formula:
||A|| = sqrt(302) * sqrt(1) / sqrt(1^2 + 0^2 + 0^2)
= sqrt(302)
Finally, to find the angle between A and B in radians, we can use the formula:
cos(theta) = (A,B) / (||A|| * ||B||)
where ||B|| is the Frobenius norm of B:
||B||F = sqrt(|-5|^2 + |-2|^2 + |-5|^2 + |-5|^2 + |-2|^2 + |-53|^2 + |3|^2)
= sqrt(294)
So, we have:
cos(theta) = -301 / (sqrt(302) * sqrt(294))
= -0.510
Taking the inverse cosine of this value, we get:
theta = 2.094 radians (rounded to three decimal places)
The frobenius inner product and the corresponding induced norm to determine the value of each of the following is Arccos((A,B) / ||A||F ||B||F) = arccos(-198 / (sqrt(305) * sqrt(54)))
≈ 1.760 radians
First, we need to calculate the Frobenius inner product of the matrices A and B:
(A,B) = tr(A^TB) = tr([55 -2 -5]^T [-5 -2 -5 3])
= tr([25 4 -25] [-5 -2 -5; 3 0 -2; 5 -5 -3])
= tr([-125-8-125 75+10+75 -125+10+15])
= tr([-258 160 -100])
= -258 + 160 - 100
= -198
Next, we can use the Frobenius norm formula to find the norm of each matrix:
||A||F = \(\sqrt(sum_i sum_j |a_ij|^2)\) = \(\sqrt(55^2 + (-2)^2 + (-5)^2) = \sqrt(305)\)
||B||F =\(sqrt(sum_i sum_j |b_ij|^2)\)=\(\sqrt(5^2 + (-2)^2 + (-5)^2 + (-3)^2 + 3^2) = \sqrt(54)\)
Finally, we can use these values to calculate the requested expressions:
(A,B) / ||A||F ||B||F = (-198) / (sqrt(305) * sqrt(54)) ≈ -6.200
||A - B||F = \(sqrt(sum_i sum_j |a_ij - b_ij|^2)\)
= \(\sqrt((55 + 5)^2 + (-2 + 2)^2 + (-5 + 5)^2 + (0 - (-3))^2 + (0 - 3)^2)\)
= \(\sqrt(680)\)
≈ 26.076
arccos((A,B) / ||A||F ||B||F) = arccos(-198 / (sqrt(305) * sqrt(54)))
≈ 1.760 radians
To know more about frobenius inner product refer here:
https://brainly.com/question/31657293
#SPJ11
Two right triangular gardens each have a shorter leg 20 feet. The length of the longer leg of one garden is twice the length of the longer leg of the other garden. The perimeter of the larger garden is 1.6 times the perimeter of the other garden. What is the approximate length of the longer leg of the smaller garden? Use a graphing calculator to help you determine the answer.
Answer:
about 24.38 feet
Step-by-step explanation:
Graphing window: [0, 30] by [-20, 160]
y1 = 20 + 2x + √(400 + 4x^2)
y2 = 1.6(20 + x + √(400 + x^2))
y1 = y2 when x = 24.3798.
So the length of the smaller garden's longer leg is about 24.38 feet.
What is the least number of degrees you could rotate a regular pentagon (5 equal side lengths) around its center so that it appears to be unchanged?
Answer:
Well, I'm not the smartest person, nor do I exactly know what you mean, but I have a wild guess that the least you could rotate it is 100 degrees.
Step-by-step explanation:
Considering the fact that it's sides are all equal, you could compare this to a square, which also has equal sides. Its angles are equal, too, so you could measure it's angles (100 degrees) and turn it that exact amount,
I hope this helps you, like I said, I don't exactly know what you are talking about, I am not studying that sort of thing yet.
13. Find the vertex of f(x)=x2 -6x +8 .
a
(3,-1)
b
(-3, 1)
c
(-3,-1)
d
(3, 1)
9514 1404 393
Answer:
a (3,-1)
Step-by-step explanation:
The number that "completes the square" is the square of half the x-coefficient, (-6/2)^2 = 9. Rearranging the given function to include the square trinomial, we have ...
f(x) = x^2 -6x +9 -1 . . . . . . . here, we have 8 = 9 - 1
f(x) = (x -3)^2 -1 . . . . . . . . . . vertex form
Comparing this to the generic vertex form ...
f(x) = (x -h)^2 +k . . . . . . . vertex at (h, k)
we see that h=3 and k=-1.
The vertex is (h, k) = (3, -1).
Estimate the quotient by rounding the expression to relate to a one-digit fact 1275 ÷ 588 A.2 B.3 C.4 D.5
Answer:
2
Step-by-step explanation:
Round the divisor to the nearest 10 or 100, depending on how many digits are in the divisor.
Round the dividend to the nearest 10, 100, or 1,000 so that all of the digits, except the first one are zeros.
Divide 600 by 30.
Compare your estimate to the exact answer to determine if the exact answer is reasonable.
A school is building a new playground. They have spent 75% of the money for the new playground. If they have spent $1200, what is the total amount of money they will spend to build the playground? ASAP
please find the value of x :)
Answer:
x = 16
Step-by-step explanation:
90 = x+8+66
x = 90-74
x = 16
Answer:
16
Step-by-step explanation:
:D
(c) A non-uniform but spherically symmetric charge distribution has a charge density: rho(r)=rho 0
(1−r/R)
rho(r)=0
for r≤R
for r>R
where rho 0
=3Q/πR 3
is a positive constant. Show that the total charge contained in this charge distribution is Q. [4] Show that the electric field in the region r>R is identical to that created by a point charge Q at r=0 [2] Derive an expression for the electric field in the region r≤R. [5]
To show that the total charge contained in the charge distribution is Q, we integrate the charge density over the entire volume. The charge density is given by:
ρ(r) = ρ₀(1 - r/R) for r ≤ R,
ρ(r) = 0 for r > R,
where ρ₀ = 3Q/πR³.
To find the total charge, we integrate ρ(r) over the volume:
Q = ∫ρ(r) dV,
where dV represents the volume element.
Since the charge density is spherically symmetric, we can express dV as dV = 4πr² dr, where r is the radial distance.
The integral becomes:
Q = ∫₀ᴿ ρ₀(1 - r/R) * 4πr² dr.
Evaluating this integral gives:
Q = ρ₀ * 4π * [r³/3 - r⁴/(4R)] from 0 to R.
Simplifying further, we get:
Q = ρ₀ * 4π * [(R³/3) - (R⁴/4R)].
Simplifying the expression inside the parentheses:
Q = ρ₀ * 4π * [(4R³/12) - (R³/4)].
Simplifying once more:
Q = ρ₀ * π * (R³ - R³/3),
Q = ρ₀ * π * (2R³/3),
Q = (3Q/πR³) * π * (2R³/3),
Q = 2Q.
Therefore, the total charge contained in the charge distribution is Q.
To show that the electric field in the region r > R is identical to that created by a point charge Q at r = 0, we can use Gauss's law. Since the charge distribution is spherically symmetric, the electric field outside the distribution can be obtained by considering a Gaussian surface of radius r > R.
By Gauss's law, the electric field through a closed surface is given by:
∮E · dA = (1/ε₀) * Qenc,
where ε₀ is the permittivity of free space, Qenc is the enclosed charge, and the integral is taken over the closed surface.
Since the charge distribution is spherically symmetric, the enclosed charge within the Gaussian surface of radius r is Qenc = Q.
For the Gaussian surface outside the distribution, the electric field is radially directed, and its magnitude is constant on the surface. Hence, E · dA = E * 4πr².
Plugging these values into Gauss's law:
E * 4πr² = (1/ε₀) * Q,
Simplifying:
E = Q / (4πε₀r²).
This is the same expression as the electric field created by a point charge Q at the origin (r = 0).
To derive an expression for the electric field in the region r ≤ R, we can again use Gauss's law. This time we consider a Gaussian surface inside the charge distribution, such that the entire charge Q is enclosed.
The enclosed charge within the Gaussian surface of radius r ≤ R is Qenc = Q.
By Gauss's law, we have:
∮E · dA = (1/ε₀) * Qenc.
Since the charge distribution is spherically symmetric, the electric field is radially directed, and its magnitude is constant on the Gaussian surface. Hence, E · dA = E * 4πr².
Plugging these values into Gauss's law:
E * 4πr² = (1/ε₀) * Q.
Simplifying:
E = Q / (4πε₀r²).
This expression represents the electric field inside the charge distribution for r ≤ R.
Learn more about charge here:
https://brainly.com/question/18102056
#SPJ11
Which of the following is the equation for the graph shown?
Answer:
x equals 0
Step-by-step explanation:
it is a vertical line on zero and this is 1st grade level math
A triangle has one side that measures 5 units and another side that
measures 7 units. What are two possible lengths for the third side?
Explain why you chose the lengths you did.
Answer:
see explanation
Step-by-step explanation:
Given 2 sides of a triangle then the third side x is between the limits
difference of 2 sides < x < sum of 2 sides, that is
7 - 5 < x < 7 + 5 , then
2 < x < 12
Choose any 2 values between 2 and 12 as third side, so
third side could be 6 or 9 for example
the radius of a sphere increases at a rate of 1 m/sec. find the rate at which the volume increases when the radius is 20 m.
We need to know about rate of change to solve the problem. The rate of change of volume of the sphere is 5026.55 sq/m.
Rate of change of a quantity is the rate at which it increases or decreases. It is given that the radius of the sphere increases at a rate of 1m/second. We need to find out the rate of change of volume of the sphere given the radius is 20m. We can calculate the rate of change of volume by calculating the derivative of volume with respect to time.
V=4/3\(\pi r^{3}\)
dV/dt=4\(\pi r^{2}\) dr/dt =4 x \(\pi\)x20x20x1=5026.55 sq m/ second
Therefore the volume of the sphere increases at a rate of 5026.55 sq/m.
Learn more about rate of change here:
https://brainly.com/question/20884505
#SPJ4
Please find what the value of x and y is!!!
Answer:
x = 3; y = 2
Step-by-step explanation:
You would just set each side equal to its opposite so for x, it'll be like:
4x+6=7x-3
and for y:
4y-3=3y+1
I attached my work below as well to help you.
Find the probability that a randomly
selected point within the circle falls in the
red-shaded square.
3
P =
3
4
Enter as a decimal rounded to the nearest hundredth.
The probability that the a point will fall on the red-shaded square to nearest hundredth is 0.56
What is probability?A probability is a number that reflects the chance or likelihood that a particular event will occur. The certainty of an event is 1 which is equivalent to 100% in decimal.
Probability = sample space / total outcome
sample space = area of shaded part
total outcome = area of the whole shape.
area of the shaded part = 3×3 = 9
area of the whole shape = 4×4 = 16
Therefore the probability that a point will fall in the shaded area = 9/16
= 0.56( nearest hundredth)
learn more about probability from
https://brainly.com/question/24756209
#SPJ1
Answer:
0.56
Step-by-step explanation:
just got it right
Assume XX has a binomial distribution. Use the binomial formula, tables, or technology to calculate the probability of the indicated event:
a. n=22, p=0.8n=22, p=0.8
P(17 ≤ X ≤ 20)=P(17 ≤ X ≤ 20)=
Round to four decimal places if necessary
b. n=21, p=0.6n=21, p=0.6
P(12 < X < 15)=P(12 < X < 15)=
Round to four decimal places if necessary
please provide correct answers..
By using binomial distribution and formula, the probability of the indicated event (a) P(17 ≤ X ≤ 20) = 0.3040 (b) P(12 < X < 15) = 0.4675.
a) Given, the distribution is binomial X ~ B(n=22, p=0.8).
Let, X1= 17 and X2 = 20. Therefore, P(17 ≤ X ≤ 20) = P(X = 17) + P(X = 18) + P(X = 19) + P(X = 20).
By using binomial formula, P(X=k) = 22Ck (0.8)^k (0.2)^(22-k).
Thus, P(X=17) = 22C17 (0.8)^17 (0.2)^5
P(X=18) = 22C18 (0.8)^18 (0.2)^4
P(X=19) = 22C19 (0.8)^19 (0.2)^3
P(X=20) = 22C20 (0.8)^20 (0.2)^2.
By putting the values, we get P(17 ≤ X ≤ 20) = 0.0040 + 0.0212 + 0.0784 + 0.2003.
The probability of the event, P(17 ≤ X ≤ 20) = 0.3039 ≈ 0.3040.
Therefore, P(17 ≤ X ≤ 20) = 0.3040
b) Given, the distribution is binomial X ~ B(n=21, p=0.6)
Let, X1= 12 and X2 = 15. Therefore, P(12 < X < 15) = P(X = 13) + P(X = 14)
By using binomial formula, P(X=k) = 21Ck (0.6)^k (0.4)^(21-k).
Thus, P(X=13) = 21C13 (0.6)^13 (0.4)^8
P(X=14) = 21C14 (0.6)^14 (0.4^)7.
By putting the values, we get P(12 < X < 15) = 0.1657 + 0.3018
The probability of the event, P(12 < X < 15) = 0.4675 ≈ 0.4675 (rounded to 4 decimal places).
Therefore, P(12 < X < 15) = 0.4675
Learn more about Binomial Distribution :
https://brainly.com/question/29163389
#SPJ11