Answer:
1. cups of coffee sold
2.Y = 605.7 - 5.943x
3. -0.952
4. 70.84
Step-by-step explanation:
1. the dependent variable in this question is the cups of coffee sold
2. least square estimation line
Y = a+bx
we have y as the cups of coffee sold
x as temperature.
first we will have to solve for a and then b
∑X = 450
∑Y = 960
∑XY = 61600
∑X² = 35500
∑Y² = 221800
a = ∑y∑x²-∑x∑xy/n∑x²-(∑x)²
a = 960 * 35500-450*61600/6*35500-450²
a = 6360000/10500
= 605.7
b = n∑xy - ∑x∑y/n∑x²-(∑x)²
= 6*61600 - 450*960/6*35500 - 450²
= -5.943
the regression line
Y = a + bx
Y = 605.7 - 5.943x
3. we are to find correlation coefficient
r = n∑xy - ∑x∑y multiplied by√(n∑x²-(∑x)² * (n∑y² - (∑y)²)
= 6*61600 -960*450/√(6*35500 - 450²)*(6*221800 - 960²)
=-62400/√4296600000
= -62400/65548.5
= -0.952
4. we have to predict sales of a 90 degree day fro the regression line
Y = 605.7 - 5.943x
y = 605.7 - 5.943(90)
y = 605.7 - 534.87
= 70.84
Two friends compete with each other and five other, equally good, violinists for first and second chair in an orchestra, in a blind competition What is the probability that the two friends end up as first and second chair together?
Answer: 0.0476
Step-by-step explanation:
Given : Two friends and 5 other people compete with each other for first and second chair in an orchestra.
Total people in this competition= 2+5=7
By permutation , Number of ways to arrange 7 people= 7!
Also, number of ways for two friends end up as first and second chair together= 2 × 5! [ 2 ways to arrange friends on first and second chair and 5! ways to arrange others]
I.e. Required probability = [tex]\dfrac{2\times5!}{7!}[/tex]
[tex]=\dfrac{2!\times5!}{7\times6\times5!}\\\\=\dfrac{1}{7\times3}\\\\=\dfrac{1}{21}\\\\=0.0476[/tex]
Hence, the probability that the two friends end up as first and second chair together = 0.0476
Please help. I’ll mark you as brainliest if correct!
Answer:
The system is dependent:
x=-3t-7
y=-5t-15
z=t
Step-by-step explanation:
I chose to use a matrix to solve this system of equations. Once put into matrix form, you need to row reduce the system into its simplest form (Row Reduced Echelon form). Doing this, we find that the system is dependent on the z variable. And following usual procedures, we let z equal some other letter; which is t in this case. Then we isolate each variable to get the answer.
Check the attachment for the work.
[The arrows indicate a row swap and the parenthesis indicates addition if a constant multiple of one row to another]
PLEASE HELP !!! (5/5) -50 POINTS-
Answer:
at least one solution
Step-by-step explanation:
Consistent solutions have at least one solution, but may have more than one solution. Intersecting lines and Lines that are the same are consistent solutions
Answer:
[tex]\boxed{Atleast\ one \ Solution}[/tex]
Step-by-step explanation:
A consistent system of equations have at least one solution. It can be more than that. There are no compulsions.
Match the provided functions to a graphed function with the same zero(s).
Answer:
1st:
[tex] {x}^{3} - 3 { x}^{2} - 3[/tex]
2nd:
[tex] {x}^{2} - 5x + 4[/tex]
3rd:
[tex] - 4x - 8[/tex]
Step-by-step explanation:
Graph all of them and see which ones cross the x- axis at the same points.
A function y = g(x) is graphed below. What is the solution to the equation g(x) = 3?
closed interval on x=3 and open at x=5
for all values between these numbers, y=3
so [3,5)
Two trains, X and Y, started simultaneously from opposite ends of a 100-mile route and traveled toward each other on parallel tracks. Train X, traveling at a constant rate, completed the 100-mile trip in 5 hours; Train Y, traveling at a constant rate, completed the 100-mile trip in 3 hours. How many miles had Train X traveled when it met Train Y?
(A) 37.5
(B) 40.0
(C) 60.0
(D) 62.5
(E) 77.5
Answer:
(A) 37.5 miles
Step-by-step explanation:
The trains x and y are travelling on tracks starting simultaneously from a from opposite ends of 100 miles roads.
Translate these information into a simple represention to visualize the problem. (Picture below)
■■■■■■■■■■■■■■■■■■■■■■■■■■
First let's calculate the velocity of both trains.
The velocity formula is:
● V = d/t
d is the distance travelled and t is the tile needed to do it.
● V(x) = 100/5 = 20 miles per hour
● V(y) = 100/3 = 33.33.. wich is approximatively 33 after rounding to the nearest unit.
■■■■■■■■■■■■■■■■■■■■■■■■■■
After calculateingboth velocities, Let's find when the trains meet.
First understand what does it mean matematically when both trains meet.
Go back to the representation and notice what happens when the trains meet.
Let t be that moment.
When x and y reches the meeting point at t, the sum of the distances they have travelled is equal to the total distance wich is 100 miles .
We khow that V = d/t so d = V×t
Let's find the expression of the distances both trains travelled when they have met each other.
● d = V(x) × t
● d' = V(y) × t
■■■■■■■■■■■■■■■■■■■■■■■■■■
So the equation will be:
● V(x) × t + V(y) × t = 100
Factor using t
● t (V(x) + V(y) ) = 100
Replace V(x) and V(y) by their values
● t (20+33) = 100
● 53 t = 100
Divide both sides by 53
● 53t /53 = 100/53
● t = 1.88
■■■■■■■■■■■■■■■■■■■■■■■■■
Replace t in the expression of the distance that train x has travelled when meeting y.
● d = V(x) × t
● d = 20 × 1.88
● d = 37.6 wich is approximatively 37.5 miles
which rate can you set 7 miles over 1 hour equal to in order to find the distance traveled in 49 hours at 7 miles per hour
Answer:
Step-by-step explanation:
time = 49 hours
speed = 7 miles/hour
speed = distance / time
∴ distance = speed × time
= 7 × 49
= 343 miles
Problem is attached in a photo
Answer:
y<(x-2)^2
Step-by-step explanation:
To graph this inequality, we first identify the function.
This is a quadratic function y=x^2
The function is translated horizontally to the right two. (x-2)^2
It is also a dotted line, <.
What is the median of these figure skating ratings?
6.0 6.0 7.0 7.0 7.0 8.0 9.0
Answer:
The median would be 7.0.
Step-by-step explanation:
The median of a set of numbers means it is the middle number. since this set has 7 numbers you would need to find the number that is in the middle of the set. This would be the 4th number since it is in the middle. 7.0 is your answer.
State the correct polar coordinate for the graph shown. It is not the option selected.
Answer:
Solution : Option D
Step-by-step explanation:
Let's start by listing two cases made possible when r is positive, in ( r, θ ). Remember that in polar coordinates a point is expressed in an ordered pair, where r is the distance from the pole (in this case 9, as it lies on the 9th circle) and theta is the directed angle from the positive x - axis.
( 9, θ ) here theta will be the angle to the terminal side with respect to the positive x - axis. This angle will be 60 degrees more than 90, or 90 + 60 = 150 degrees
( 9, θ ) and here theta will be the remaining degrees, or 360 - 150 = 210 degrees. Right away your solution will be (9, 210°)
Henry takes out a $650 discounted loan with a simple interest rate of 12% for a period of 7 months. How much money does Henry receive into his bank account when the loan is drawn down? Give your answer to the nearest cent.
Answer:
$546
Step-by-step explanation:
Given
Amount, P = $650
Rate, R = 12%
Period, T = 7 months
Required
Determine the amount paid.
We'll solve this using simple interest formula, as thus
[tex]I = \frac{PRT}{100}[/tex]
Substitute values for T, R and P
[tex]I = \frac{\$650 * 12 * 7}{100}[/tex]
[tex]I = \frac{\$54600}{100}[/tex]
[tex]I = \$546[/tex]
Hence, Henry's withdrawal is $546
At a store An orange costs 18 cents A pineapple costs 27 cents An apple costs 15 cents How much does a strawberry cost??
Answer:
A strawberry cost 30 cents
Step-by-step explanation:
Given:
Orange= 18 cents
Pineapple = 27 cents
Apple = 15 cents
Strawberry = ?
From the given:
Orange has 6 letters multiplied by 3
=6 * 3
=18 cents
Pineapple has 9 letters multiplied by 3
=9 * 3
=27 cents
Apple has 5 letters multiplied by 3
= 5 * 3
= 15 cents
Therefore, cost of the strawberry=
Strawberry has 10 letters. Multiply the 10 letters by 3
That is,
10 × 3
= 30 cents
Help me please ?! ❤️❤️
Answer:
Hey there!
Point K has coordinates of (-2, -5)
Hope this helps :)
Answer:
Point K
Step-by-step explanation:
Since they're asking us to find (-2,-5) first we need to move 2 points to the left and then 5 points down.
The time it takes to install a certain hardware is random. A technician installs this hardware on 64 computers with the average installation time being 42 minutes and the standard deviation of the times being 5 minutes. What is a 90% confidence interval for the popu
Answer:
[tex]40.97<\mu<43.03[/tex]
Step-by-step explanation:
Th formula for calculating the confidence interval of a population is expressed as shown;
CI = xbar ± Z*S/√n where;
xbar is the mean or average sample
Z is the z-score at 90% confidence
S is the standard deviation
n is the sample size
Given parameters
xbar = 42
Z at 90% CI = 1.645
S = 5
n = 64
Substituting the values into the formula will give;
CI = 42±(1.645*5/√64)
CI = 42±(1.645*5/8)
CI = 42±(1.645*0.625)
CI = 42±1.028125
CI = (42-1.028125, 42+1.028125)
CI = (40.971875, 43.028125)
Hence the 90% confidence interval for the population is approximately (40.97, 43.03) i.e [tex]40.97<\mu<43.03[/tex]
What is the equation of the following line? Be sure to scroll down first to see all answer options.
A.
y = - 1/2x
B.
y = 1/2x
C.
y = 2x
D.
y = -6x
E.
y = 6x
F.
y = 3x
Answer:
y=-6x
Step-by-step explanation:
If the true mean is 50 and we reject the hypothesis that μ = 50, what is the probability of Type II error? Hint: This is a trick question.
Answer:
Zero
Step-by-step explanation:
Given that:
the true mean is 50 and we reject the hypothesis that μ = 50
The probability of the Type II error will be zero, given that we reject the null hypothesis. This has nothing to do with if it is true or false.
Type II error is occurs when you accept a false null hypothesis. The probability of this error is denoted by beta which relies on sample size and population variance.
The probability of rejecting is equal to one minu beta. i.e it is the researchers goal to reject a false null hypothesis.
Does the function satisfy the hypotheses of the Mean Value Theorem on the given interval? f(x) = 4x2 − 3x + 2, [0, 2]
Answer:
Yes , it satisfies the hypothesis and we can conclude that c = 1 is an element of [0,2]
c = 1 ∈ [0,2]
Step-by-step explanation:
Given that:
[tex]f(x) = 4x^2 -3x + 2, [0, 2][/tex]
which is read as the function of x = 4x² - 3x + 2 along the interval [0,2]
Differentiating the function with respect to x is;
f(x) = 8x - 3
Using the Mean value theorem to see if the function satisfies it, we have:
[tex]f'c = \dfrac{f(b)-f(a)}{b-a}[/tex]
[tex]8c -3 = \dfrac{f(2)-f(0)}{2-0}[/tex]
since the polynomial function is differentiated in [0,2]
[tex]8c -3 = \dfrac{(4(2)^2-3(2)+2)-(4(0)^2-3(0)+2)}{2-0}[/tex]
[tex]8c -3 = \dfrac{(4(4)-3(2)+2)-(4(0)-3(0)+2)}{2-0}[/tex]
[tex]8c -3 = \dfrac{(16-6+2)-(0-0+2)}{2-0}[/tex]
[tex]8c -3 = \dfrac{(12)-(2)}{2}[/tex]
[tex]8c -3 = \dfrac{10}{2}[/tex]
8c -3 = 5
8c = 5+3
8c = 8
c = 8/8
c = 1
Therefore, we can conclude that c = 1 is an element of [0,2]
c = 1 ∈ [0,2]
Solve the equation for x by graphing.-4x-1 5x=4
Answer: Undefined
Step-by-step explanation:
slope is undefined
no y intercept
This line is vertical
To the nearest square inch, what is the surface area of the square pyramid shown in the image? A. 175 in.^2 B. 200 in.^2 C. 400 in.^2 D. 700 in.^2 Please show ALL work! :D
Answer: C. 400 in^2
Step-by-step explanation:
First find the surface area or the area of the base which is in the shape of a square and has a side length of 10 in. So square 10 to find the area.
Area of base: 10 * 10 = 100
Next find the area of one of the triangles.
As we could see the triangle has a slant height of 15 in and a base of 10. To find the area of a triangle we multiply the base times the height and multiply it by half.
Area of one triangle. 15 * 10 = 150 * 1/2 = 75
Since one side of the triangle has a surface area of 75 inches we will multiply it by 4 since there are four triangles to find the total surface area of the four faces.
75 * 4 = 300
We now know that the the 4 triangles surface area dd up to 300 so we will add it to the area of the base which is 100 to find the whole surface area of the figure.
300 + 100 = 400
Area And Perimeter! Find the Area and the Perimeter of the Triangle!!! and explain.... ( help hurry!!)
perimeter of triangle: P = l+w+h
9+12+10= 31in.
area of triangle: A=b×h÷2
21 + 21 = 42in^2
4. Katy has 6 times as many nickels as
Shaun. Shaun has 18 nickels. How many
nickels, n, does Katy have?
n is 6
18.
n=
Answer:
[tex]\huge\boxed{n = 108\ nickels}[/tex]
Step-by-step explanation:
Let the nickels with Katy be n
So, the condition is
n = 6 (Shaun nickels)
While Nickels of Shaun = 18 , So
n = 6 (18)
n = 108 nickels
PLS HELP !!
Define two terms, each containing the variables x and y, with exponents on each. (For Example : 10x³y–⁵)Find the quotient of the two terms. Explain step-by-step how you found the quotient
Answer:
Step-by-step explanation:
Two such terms are 7x^3*y^9 and -3x*y^5
Their quotient is
7x^3*y^9
--------------
-3x*y^5
This can be simplified as follows:
The numerical coefficients become -7/3.
x^3/x = x^3*x^1 = x^(3 - 1) = x^2 (we subtract the exponent of x in the denominator from the exponent of x in the numerator).
Next, y^9*y^5 = y^4.
The quotient in final reduced form is then (-7/3)x^2*y^4
We want to model the daily movement of a particular stock (say Amazon, ticker = AMZN) using a homogeneous markov-chain. Suppose at the close of the market each day, the stock can end up higher or lower than the previous day’s close. Assume that if the stock closes higher on a day, the probability that it closes higher the next day is .65. If the stock closes lower on a day, the probability that it closes higher the next day is .45.
(a) What is the 1-step transition matrix? (Let 1 = higher, 2 = lower)
(b) On Monday, the stock closed higher. What is the probability that it will close higher on Thursday (three days later)
Answer:
See the explanation and attached images for the answers.
Step-by-step explanation:
a) 1-step transition matrix:
See the attached image for transition matrix.
Let the matrix be M
if the stock closes higher on a day, the probability that it closes higher the next day is 0.65.
If the stock closes lower on a day, the probability that it closes higher the next day is 0.45
if the stock closes higher on a day, the probability that it closes lower the next day is 1 - 0.65 = 0.35
if the stock closes lower on a day, the probability that it closes lower the next day is 1 - 0.45 =0.55
b)
To compute probability for 3 days later multiply matrix M (from part a) thrice i.e. M*M *M
[tex]M^{3} = \left[\begin{array}{ccc}0.65&0.35\\0.45&0.55\end{array}\right]*\left[\begin{array}{ccc}0.65&0.35\\0.45&0.55\end{array}\right]*\left[\begin{array}{ccc}0.65&0.35\\0.45&0.55\end{array}\right][/tex]
[tex]M^{3} = \left[\begin{array}{ccc}0.65 * 0.65 + 0.35 * 0.45 &0.65 * 0.35 + 0.35 * 0.55 \\0.45 * 0.65 + 0.55 * 0.45 &0.45 * 0.35 + 0.55 * 0.55 \end{array}\right] * \left[\begin{array}{ccc}0.65&0.35\\0.45&0.55\end{array}\right][/tex]
[tex]M^{3} = \left[\begin{array}{ccc}0.58&0.42\\0.54&0.46\end{array}\right]*\left[\begin{array}{ccc}0.65&0.35\\0.45&0.55\end{array}\right][/tex]
[tex]M^{3} = \left[\begin{array}{ccc} 0.58 * 0.65 + 0.42 x 0.45&0.58 * 0.35 + 0.42 * 0.55 \\0.54 * 0.65 + 0.46 * 0.45 &0.54 * 0.35 + 0.46 * 0.55 \end{array}\right][/tex]
[tex]M^{3} = \left[\begin{array}{ccc}0.566&0.434\\0.558&0.442\end{array}\right][/tex]
The probability that it will close higher on Thursday is 0.566. See the transmission matrix of M³ for higher-higher. This can be interpreted as:
if the stock closed higher on Monday, the probability that it closes higher the on Thursday (three days later) is 0.566
Find the missing coordinate
Answer:
(0, -10a)
Step-by-step explanation:
From the picture attached,
Coordinates of a point have been given as (-10a, 0)
x-coordinate → distance of the point from the origin on x-axis
y-coordinate → distance of the point from the origin on y-axis
Therefore, distance of the given point on x-axis = -10a [(-) sign denotes the negative side of the x-axis]
Distance of the other point with unknown coordinates (x, y) (on y-axis) from the origin = y
And y = 10a
Therefore, coordinates of the unknown point will be (0, -10a).
[Here (-) sign denotes the negative side of the y-axis]
Quick! Andrew has to play 15 games in a chess tournament. At some point during the tournament he has won half of the games he has played, he has lost one-third of the games he has played and two have ended in a draw. How many games has Andrew still to play?
[tex]x[/tex] - the number of the games he played
[tex]\dfrac{x}{2}[/tex] - the number of the games he won
[tex]\dfrac{x}{3}[/tex] - the number of the games he lost
[tex]x=\dfrac{x}{2}+\dfrac{x}{3}+2\Big|\cdot6\\6x=3x+2x+12\\x=12[/tex]
[tex]15-12=3[/tex]
so, he has still 3 games to play
find the area of square whose side is 2.5 cm
Answer:
6.25
Step-by-step explanation:
2.5 *2.5=6.25
Answer:
6.25cm^2.
Step-by-step explanation:
To find the area of a square, you multiply the two sides, 2.5✖️2.5.
This gives the area of 6.25cm^2.
Hope this helped!
Have a nice day:)
Salina currently has an account balance of $1,047.69. Her initial deposit on the account was $630 and it earned 3.9% simple interest. How long has Salina held the account?
A - 17 years
B - 26 years
C - 10 years
D - 43 years
Answer:
A. 17 years
Step-by-step explanation:
Use the simple interest equation, I = prt, where I is the interest money gained, p is the starting amount of money, r is the interest rate in decimal form, and t is the time in years.
Plug in the values to solve for t:
417.69 = (630)(0.039)(t)
417.69 = 24.57t
17 = t
= 17 years
So, the correct answer is A, 17 years
A rectangular tank that is 2048 ft cubed with a square base and open top is to be constructed of sheet steel of a given thickness. Find the dimensions of the tank with minimum weight.
Answer:
16ft by 16ft by 8ft.
Step-by-step explanation:
Let the total surface area of the rectangular tank be S = 2LW+2LH+2WH where;
L is the length of the box
W is the width of the box
H is the height of the box.
Since the box is openend at the top, S = lw + 2lh+ 2wh
If the base is a square base then, l = w
S = l(l) + 2wh+2wh
S = l²+4wh ............... 1
If volume = lwh
lwh = 2028 ft³
wh = 2048/l ................ 2
Substitute equation 2 into 1;
S = l²+4(2048/l)
S = l²+8192/l
dS/dl = 2l - 8192/l²
If dS/dl = 0 (since we are looking for dimensions of the tank with minimum weight.)
2l - 8192/l² = 0
2l = 8192/l²
2l³ = 8192
l³ = 8192/2
l³ = 4096
l =∛4096
l = 16 ft
Since the length is equal to the width, hence the width = 16ft (square based tank)
Given the volume V = lwh = 2048
lwh = 2048
16*16*h = 2048
256h = 2048
divide both sides by 256
256h/256 = 2048/256
h = 8ft
Hence, the dimensions of the tank with minimum weight is 16ft by 16ft by 8ft.
one third multiplied by the sum of a and b
Answer:
1/3(a+b)
hope it helps :>
Need help finding the value for A
Answer:
[tex]\text{n}(A \bigcup B)[/tex] = 6.
Step-by-step explanation:
We are given that n(A) = 4, n(B) = 5, and [tex]\text{n}(A \bigcap B)[/tex] = 3.
And we have to find the value of [tex]\text{n}(A \bigcup B)[/tex].
As we know that the union formula is given by;
[tex]\text{n}(A \bigcup B) = \text{n}(A) + \text{n}(B) - \text{n}(A \bigcap B)[/tex]
Now, substituting the values given in the question in the above formula, we get;
[tex]\text{n}(A \bigcup B) = 4+5-3[/tex]
[tex]\text{n}(A \bigcup B) = 9-3[/tex]
[tex]\text{n}(A \bigcup B) = 6[/tex]
Hence, the value of [tex]\text{n}(A \bigcup B)[/tex] = 6.
