The table below gives the list price and the number of bids received for five randomly selected items sold through online auctions. Using this data, consider the equation of the regression line, yˆ=b0+b1x, for predicting the number of bids an item will receive based on the list price. Keep in mind, the correlation coefficient may or may not be statistically significant for the data given. Remember, in practice, it would not be appropriate to use the regression line to make a prediction if the correlation coefficient is not statistically significant.Price in Dollars 23 34 40 46 47Number of Bids 1 3 4 5 7Step 1 of 6:Find the estimated slope. Round your answer to three decimal places.Step 2 of 6:Find the estimated y-intercept. Round your answer to three decimal places.Step 3 of 6:Determine if the statement "All points predicted by the linear model fall on the same line" is true or false.Step 4 of 6:Find the estimated value of y when x=46. Round your answer to three decimal places.Step 5 of 6:Determine the value of the dependent variable y^ at x=0.Step 6 of 6:Find the value of the coefficient of determination. Round your answer to three decimal places.
Answers
Answer:
1) Estimated slope = b₁ = 0.215
2) Estimated y-intercept = b₀ = -4.185
3) Not all the points predicted fall on the same straight line, but the model gives a close to ideal estimate of the line of best fit.
4) The estimated value of y when x=46 is 5.705
5) The value of the dependent variable y^ at x=0 is -4.185
6) The coefficient of determination = 0.951
Step-by-step explanation:
To solve this, we apply regression analysis
y = b₀ + b₁x
Price in Dollars | 23 | 34 | 40 | 46 | 47
Number of Bids | 1 | 3 | 4 | 5 | 7
For this question, we want to predict the number of bids (dependent variable, y), given the list price of the item (independent variable, x)
So, running the analysis on a spreadsheet application, like excel, the table of parameters is obtained and presented in the first attached image to this solution.
Σxᵢ = sum of all the independent variables (sum of all the list prices)
Σyᵢ = sum of all the dependent variables (sum of all the number of bids in the table)
Σxᵢyᵢ = sum of the product of each dependent variable and its corresponding independent variable
Σxᵢ² = sum of the square of each independent variable (list prices)
Σyᵢ² = sum of the square of each dependent variable (number of bids)
n = number of variables = 5
The scatter plot and the line of best fit is presented in the second attached image to this solution
Then the regression analysis is then done
Slope; m = b₁ = [n×Σxᵢyᵢ - (Σxᵢ)×(Σyᵢ)] / [nΣxᵢ² - (∑xi)²]
Intercept b: b₀ = [Σyᵢ - m×(Σxᵢ)] / n
Mean of x = (Σxᵢ)/n
Mean of y = (Σyᵢ) / n
Sample correlation coefficient r: r =
[n*Σxᵢyᵢ - (Σxᵢ)(Σyᵢ)] ÷ {√([n*Σxᵢ² - (Σxᵢ)²][n*Σyᵢ² - (Σyᵢ)²])}
And -1 ≤ r ≤ +1
All of these formulas are properly presented in the third attached image to this answer
The table of results; mean of x, mean of y, intercept, slope, regression equation and sample coefficient is presented in the fourth attached image to this answer.
Hence, the regression equation is
y = -4.185 + 0.215x
y = b₀ + b₁x
Intercept = b₀ = -4.185
Slope = b₁ = 0.215
And the regression coefficient = 0.951 (Which is very close to 1 and indicates statistic significance)
Hence, we can use this answer obtained to answer the questions attached
1) Find the estimated slope.
Estimated slope = b₁ = 0.215
2) Find the estimated y-intercept.
Estimated y-intercept = b₀ = -4.185
3) Determine if the statement "All points predicted by the linear model fall on the same line" is true or false.
Taking a few of sample data
x = 23 when y = 1
y = -4.185 + 0.215x
y = -4.185 + 0.215 (23) = 0.76 ≈ 1
x = 34, y = 3
y = -4.185 + 0.215 (34) = 3.125 ≈ 3
Hence, it is evident that not all the points predicted fall on the same straight line, but the model gives a close to ideal estimate of the line of best fit.
4) Find the estimated value of y when x=46.
The linear model is
y = -4.185 + 0.215x
when x = 46
y = -4.185 + 0.215(46) = 5.705
5) Determine the value of the dependent variable y^ at x=0.
y = -4.185 + 0.215x
when x = 0
y = -4.185 + 0.215(0) = -4.185
6) Find the value of the coefficient of determination.
The coefficient of determination = regression coefficient = 0.951 (as calculated above)
Hope this Helps!!!
Related Questions
ASAP! GIVING BRAINLIEST! Please read the question THEN answer CORRECTLY! NO guessing. I say no guessing because people usually guess on my questions.
Answers
Answer:
D. F(x) = 2(x-3)^2 + 3
Step-by-step explanation:
We are told that the graph of G(x) = x^2, which is a parabola centered at (0, 0)
We are also told that the graph of the function F(x) resembles the graph of the function G(x) but has been shifted and stretched.
The graph of F(x) shown is facing up, so we know that it is multiplied by a positive number. This means we can eliminate A and C because they are both multiplied by -2.
Our two equations left are:
B. F(x) = 2(x+3)^2 + 3
D. F(x) = 2(x-3)^2 + 3
Well, we can see that the base of our parabola is (3, 3), so let's plug in the x value, 3, and see which equation gives us a y-value of 3.
y = 2(3+3)^2 + 3 =
2(6)^2 + 3 =
2·36 + 3 =
72 + 3 =
75
That one didn't give us a y value of 3.
y = 2(3-3)^2 + 3 =
2(0)^2 + 3 =
2·0 + 3 =
0 + 3 =
3
This equation gives us an x-value of 3 and a y-value of 3, which is what we wanted, so our answer is:
D. F(x) = 2(x-3)^2 + 3
Hopefully this helps you to understand parabolas better.
To test for the significance of a regression model involving 3 independent variables and 47 observations, the numerator and denominator degrees of freedom (respectively) for the critical value of F are _____.
Answers
Answer:
The degrees of freedom for the numerator on this case is given by [tex]df_{num}=df_{within}=k=3[/tex] where k =3 represent the number of independent variables.
The degrees of freedom for the denominator on this case is given by [tex]df_{den}=df_{between}=N-p-1=47-3-1 =43[/tex].
And the total degrees of freedom would be [tex]df=N-1=47 -1 =46[/tex]
And then the degrees of freedom for the numerator are 3 and for the denominator are 43 in order to find the critical value [tex]F_{3,43}[/tex]
Step-by-step explanation:
We need to take in count that we are conducting a regression model with just one dependent variable and 3 independent variables
The degrees of freedom for the numerator on this case is given by [tex]df_{num}=df_{within}=k=3[/tex] where k =3 represent the number of independent variables.
The degrees of freedom for the denominator on this case is given by [tex]df_{den}=df_{between}=N-p-1=47-3-1 =43[/tex].
And the total degrees of freedom would be [tex]df=N-1=47 -1 =46[/tex]
And then the degrees of freedom for the numerator are 3 and for the denominator are 43 in order to find the critical value [tex]F_{3,43}[/tex]
Solve the equation.
3(x + 1)-1=3x+2
Answers
Answer:
0=0
Step-by-step explanation:Let's solve your equation step-by-step.
3(x+1)−1=3x+2
Step 1: Simplify both sides of the equation.
3(x+1)−1=3x+2
(3)(x)+(3)(1)+−1=3x+2(Distribute)
3x+3+−1=3x+2
(3x)+(3+−1)=3x+2(Combine Like Terms)
3x+2=3x+2
3x+2=3x+2
Step 2: Subtract 3x from both sides.
3x+2−3x=3x+2−3x
2=2
Step 3: Subtract 2 from both sides.
2−2=2−2
0=0
mp
3x+3-1=3x+2
Cancel each terms on each side
3-1=2
Subtract the numbers
2=2
The statement is true for any value of X
Chocolate chip cookies have a distribution that is approximately normal with a mean of 23.1 chocolate chips per cookie and a standard deviation of 2.9 chocolate chips per cookie. Find Upper P 10 and Upper P 90. How might those values be helpful to the producer of the chocolate chip cookies?
Answers
Answer:
[tex]z=-1.28<\frac{a-23.1}{2.9}[/tex]
And if we solve for a we got
[tex]a=23.1 -1.28*2.9=19.388[/tex]
And for the 90 percentile we can do this:
[tex]z=1.28<\frac{a-23.1}{2.9}[/tex]
And if we solve for a we got
[tex]a=23.1 +1.28*2.9=26.812[/tex]
The P10 would be 19.388 and the P90 26.812
Step-by-step explanation:
Let X the random variable that represent the chocolate chip cookies of a population, and for this case we know the distribution for X is given by:
[tex]X \sim N(23.1,2.9)[/tex]
Where [tex]\mu=23.1[/tex] and [tex]\sigma=2.9[/tex]
For this part we want to find a value a, such that we satisfy this condition:
[tex]P(X>a)=0.90[/tex] (a)
[tex]P(X<a)=0.10[/tex] (b)
We can find a z score value who that satisfy the condition with 0.10 of the area on the left and 0.90 of the area on the right it's z=-1.28.
Using this value we can do this:
[tex]P(X<a)=P(\frac{X-\mu}{\sigma}<\frac{a-\mu}{\sigma})=0.10[/tex]
[tex]P(z<\frac{a-\mu}{\sigma})=0.10[/tex]
And we can solve for the value of interest
[tex]z=-1.28<\frac{a-23.1}{2.9}[/tex]
And if we solve for a we got
[tex]a=23.1 -1.28*2.9=19.388[/tex]
And for the 90 percentile we can do this:
[tex]z=1.28<\frac{a-23.1}{2.9}[/tex]
And if we solve for a we got
[tex]a=23.1 +1.28*2.9=26.812[/tex]
The P10 would be 19.388 and the P90 26.812
Your company made $120,000 in revenue and $50,000 in costs for 2017. What was your profit?
Answers
Answer:
$70,000
Step-by-step explanation:
Profit = Revenue - Costs
x = 120,000 - 50,000
x = 70,000
A spinner has 10 equally sized sections, 8 of which are gray and 2 of which are blue. The spinner is spun twice. What is the probability that the first spin lands on gray and the second spin lands on blue ? Write your answer as a fraction in simplest form.
Answers
Answer:
4/25
Step-by-step explanation:
The probability the first spin lands on gray is 8/10 = 4/5.
The probability the second spin lands on blue is 2/10 = 1/5.
The probability of both events is 4/5 × 1/5 = 4/25.
In a college of exactly 2800 students, exactly 55 % are male. What is the number of female students? Express your answer as an integer.
Answers
A random sample of 18 graduates of a certain secretarial school typed an average of 80.6 words per minute with a standard deviation of 7.2 words per minute. Assuming a normal distribution for the number of words typed per minute, compute the 95% prediction interval for the next observed number of words per minute typed by a graduate of the secretarial school.
Answers
Answer: ( 77.27 , 83.93)
Therefore at 95% confidence/prediction interval is
= ( 77.27 , 83.93)
Step-by-step explanation:
Confidence interval can be defined as a range of values so defined that there is a specified probability that the value of a parameter lies within it.
The confidence interval of a statistical data can be written as.
x+/-zr/√n
Given that;
Mean x = 80.6 words per minute
Standard deviation r = 7.2
Number of samples n = 18
Confidence interval = 95%
z(at 95% confidence) = 1.96
Substituting the values we have;
80.6+/-1.96(7.2/√18)
80.6+/-1.96(1.697056274847)
80.6 +/- 3.33
= ( 77.27 , 83.93)
Therefore at 95% confidence/prediction interval is
= ( 77.27 , 83.93)
How many degrees was ABCD rotated?
Answers
the answer is 180°
Step-by-step explanation:
because it rotated 2x and 90+90 is 180
Grandmother bought enough cat food for her four cats to last for 12 days. On her way home she brought back two stray cats. If she gives each cat the same amount of food every day, how many days will the cat food last
Answers
Answer:
The number of days the cat food will last is 8 days.
Step-by-step explanation:
In this case, it it provided that Grandmother bought enough cat food for her four cats to last for 12 days.
Assume that each cat consumes x portions of food each day.
Then the four cats will consume, 4x portions of food each day.
Then in 12 days the amount of food consumed by the 4 cats will be:
Total amount of cat food = 12 × 4x
= 48x.
Now, it is provided that she on her way home she brought back two stray cats.
Then the six cats will consume, 6x portions of food each day.
Compute the number of days the cat food will last as follows:
[tex]\text{Number of days the cat food will last}=\frac{\text{Total amount of cat food}}{\text{Amount of food consumed each day}}[/tex]
[tex]=\frac{48x}{6x}\\\\=\frac{48}{6}\\\\=8[/tex]
Thus, the number of days the cat food will last is 8 days.
A bread machine produces 159 loaves of bread per hour. The machine operates 10 hours per day. How many loaves of bread does it produce per day? _____ loaves
Answers
Answer:
It can produce 1590 loaves of bread per day.
Step-by-step explanation:
Given that the bread machine operates only 10 hours per day. So in order to calculate how many loaves can be produce a day, you have to multiply it by 10 :
[tex]1hour = 159loaves[/tex]
[tex]10hours = 159 \times 10[/tex]
[tex]10hours = 1590loaves[/tex]
what is 12/5 as a mixed nunber
Answers
Answer:
2 2/5
Step-by-step explanation:
12/5
5 goes into 12 2 times
12 - 5*2
12-10 =2
There is 2 left over. This goes over the denominator
2 2/5
Banking fees have received much attention during the recent economic recession as banks look for ways to recover from the crisis. A sample of 41 customers paid an average fee of $12.22 per month on their interest-bearing checking accounts. Assume the population standard deviation is $1.86. Complete parts a and b below.
a. Construct a 95% confidence interval to estimate the average fee for the population.
b. What is the margin of error for this interval?
Answers
Answer:
a) The 95% confidence interval to estimate the average fee for the population is between $11.65 and $12.79
b) $0.57
Step-by-step explanation:
We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:
[tex]\alpha = \frac{1-0.95}{2} = 0.025[/tex]
Now, we have to find z in the Ztable as such z has a pvalue of [tex]1-\alpha[/tex].
So it is z with a pvalue of [tex]1-0.025 = 0.975[/tex], so [tex]z = 1.96[/tex]
Now, find the margin of error M as such
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
[tex]M = 1.96*\frac{1.86}{\sqrt{41}} = 0.57[/tex]
So the answer for b) is $0.57.
The lower end of the interval is the sample mean subtracted by M. So it is 12.22 - 0.57 = $11.65
The upper end of the interval is the sample mean added to M. So it is 12.22 + 0.57 = $12.79
The 95% confidence interval to estimate the average fee for the population is between $11.65 and $12.79
What is 9/8 squaredto the power of 2 ?
Answers
1.265
Or
81/64
Answer:
81/64
Step-by-step explanation:
(9/8)²=9²/8²=81/64
A firm produces a commodity and receives $100 for each unit sold. The cost of producing and selling x units is 20x 0.25x 2 dollars. Find the number of units the company should produce in order to maximize profit, and find the maximum profit.
Answers
Answer:
160 units and $6400
Step-by-step explanation:
We have that the cost per x unit is: 20 * x + 0.25 * x ^ 2
the price per unit is 100, therefore revenue for each unit would be 100 * x
However:
profit = revenue - cost
p (x) = 100 * x - 20 * x - 0.25 * x ^ 2
for the maximum value profit we must derive and equal 0:
p '(x) = 100 - 20 - 0.5 * x
0 = 80 - 0.5 * x
0.5 * x = 80
x = 80 / 0.5
x = 160
Therefore, the maximum profit occurs when there are 160 units, replacing we have:
p (x) = 100 * 160 - 20 * 160 - 0.25 * 160 ^ 2
p (x) = 6400
that is to say that the $ 6400 is the maximum profit.
What’s the correct answer for this question?
Answers
Answer:
B) (1,2,3,4,5,6,7,8)
Step-by-step explanation:
The answer is B because the union of a set represents everything thing that is within the sets.
which is the domain of f(x) = 4^x
will give brainlist!
Answers
Answer:
all real numbers
Step-by-step explanation:
The domain is the input values
All values for x are valid as inputs to the function
If log10y=2, what does y equal?
Answers
Answer:
[tex]y=100[/tex]
Step-by-step explanation:
I don't know if by the 10 you mean the base is 10 or it's being logged with the y, but I'm assuming the base is 10. If that's not right, message me and I'll fix my answer. If,
[tex]log_an=x\\a^x=n[/tex]
Then,
[tex]log_1_0y=2\\10^2=y\\100=y[/tex]
Simplify 6r · s · 4rt. this is the question
Answers
Answer=6 . S/R . 4T
This is the answer because u have to simplify so to do this u have to divide all of this by R
The mean of the data set(9,5,y,2,x) is twice the data set(8,x,4,1,3).what is (y-x)
Answers
Answer:
[tex]y-x = 16[/tex]
Step-by-step explanation:
Given
Set 1: (9,5,y,2,x)
Set 2: (8,x,4,1,3)
Required
(y - x)
First the mean values of set 1 and set 2 has to be calculated
For set 1
[tex]Mean _1 = \frac{(9+5+y+2+x)}{5}[/tex]
Collect like terms
[tex]Mean _1 = \frac{9+5+2+y+x}{5}[/tex]
[tex]Mean _1 = \frac{16+ y+x}{5}[/tex]
For set 2
[tex]Mean _2 = \frac{(8+x+4+1+3)}{5}[/tex]
Collect like terms
[tex]Mean _2 = \frac{8+4+1+3+x}{5}[/tex]
[tex]Mean _2= \frac{16+ x}{5}[/tex]
Given that the mean of set 1 is twice the mean of set 2;
[tex]Mean_1 = 2Mean_2[/tex]
[tex]\frac{16+ y+x}{5} =2 * \frac{16+x}{5}[/tex]
Multiply both sided by 5
[tex]5 * \frac{16+ y+x}{5} = 5 * 2 * \frac{16+x}{5}[/tex]
[tex]16+ y+x = 2 * (16+x)[/tex]
Open bracket
[tex]16+ y+x = 32 + 2x[/tex]
Subtract 16 from both sides
[tex]16+ y+x- 16 = 32 + 2x - 16[/tex]
[tex]16 - 16 + y+x = 32 - 16 + 2x[/tex]
[tex]y+x = 16 + 2x[/tex]
Subtract 2x from both sides
[tex]y+x-2x = 16 + 2x-2x[/tex]
[tex]y-x = 16[/tex]
Question 1 Muit Choice Worth 1 points)
(08.01 LC)
The school principal wants to know whether the students in the entire school prefer football or basketball. The principal draws a random sample from the following groups:
• All school teachers
. All girls in each grade
. All students in each grade
• All students on the basketball team
Which of the following groups best represents the population she should take a random sample from to get the best results for her survey?
All school teachers
All girls in each grade
All students in each grade
All students on the basketball team
Answers
Answer:
I think its C. All students in each grade
Step-by-step explanation:
because it should be the students choice.
A laundry basket has 24 shirts in it for our Navy 12 arete and the remaining our way what is the probability of selecting a red shirt
Answers
Answer:
[tex]P(selecting a red t-shirt)=1/2[/tex]
Step-by-step explanation:
CHECK THE COMPLETE QUESTION BELOW;
A laundry basket has 24 t-shirts in it. Four are Navy, 12 are red, and the rest is white. What is the probability of randomly selecting a red t-shirt
EXPLANATION
Total number of the t-shirt in the laundry basket = 24
Number of Navy t-shirt = 4
Number of red t- shirt = 12
The number of white t- shirt in the laundry basket can be calculated as follow;
Total number of t- shirt - (Number of Navy t-shirt + Number of red t- shirt)
Number of white t- shirt = 24 -(4+12)
Number of white t- shirt = 8
The probability of randomly selecting a red t-shirt = [tex]Number of red t- shirt/Total number of the t-shirt[/tex]
[tex]P(selecting a red t-shirt)=12/24[/tex]
[tex]P(selecting a red t-shirt)=1/2[/tex]
3.14 The waiting time, in hours, between successive speeders spotted by a radar unit is a continuous random variable with cumulative distribution function F(x) = 0, x< 0, 1 − e−8x, x ≥ 0. Find the probability of waiting less than 12 minutes between successive speeders (a) using the cumulative distribution function of X; (b) using the probability density function of X.
Answers
Answer:
(a) The probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function is 0.7981.
(b) The probability of waiting less than 12 minutes between successive speeders using the probability density function is 0.7981.
Step-by-step explanation:
The cumulative distribution function of the random variable X, the waiting time, in hours, between successive speeders spotted by a radar unit is:
[tex]F(x)=\left \{ {{0;\ x<0} \atop {1-e^{-9x};\ x\geq 0}} \right.[/tex]
(a)
Compute the probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function as follows:
[tex]12\ \text{minutes}=\frac{12}{60}=0.20\ \text{hours}[/tex]
The probability is:
[tex]P(X<0.20)=|F (x)|_{x=0.20}[/tex]
[tex]=(1-e^{-8x})|_{x=0.20}\\\\=1-e^{-8\times 0.20}\\\\=0.7981[/tex]
Thus, the probability of waiting less than 12 minutes between successive speeders using the cumulative distribution function is 0.7981.
(b)
The probability density function of X is:
[tex]f_{X}(x)=\frac{d F (x)}{dx}=\left \{ {{0;\ x<0} \atop {8e^{-8x};\ x\geq 0}} \right.[/tex]
Compute the probability of waiting less than 12 minutes between successive speeders using the probability density function as follows:
[tex]P(X<0.20)=\int\limits^{0.20}_{0} {8e^{-8x}} \, dx[/tex]
[tex]=8\times [\frac{-e^{-8x}}{8}]^{0.20}_{0}\\\\=[-e^{-8x}]^{0.20}_{0}\\\\=(-e^{-8\times 0.20})-(-e^{-8\times 0})\\\\=-0.2019+1\\\\=0.7981[/tex]
Thus, the probability of waiting less than 12 minutes between successive speeders using the probability density function is 0.7981.
The probability of drawing a pearl bead out of a bag of mixed beads is 2/3. What is the probability of drawing a bead which is not a pearl?
Answers
Answer:
[tex]\frac{1}{3}[/tex] probability of drawing a bead which is not a pearl
Step-by-step explanation:
For each bead that you draw, there are only two possible outcomes. Either it is a pearl bead, or it is not. The sum of these probabilities = 100% = 1.
So
2/3 probability of drawing a pearl bead.
p probability of drawing a non pearl bead.
What is the probability of drawing a bead which is not a pearl?
[tex]p + \frac{2}{3} = 1[/tex]
[tex]p = 1 - \frac{2}{3}[/tex]
[tex]p = \frac{3*1 - 2}{3}[/tex]
[tex]p = \frac{1}{3}[/tex]
[tex]\frac{1}{3}[/tex] probability of drawing a bead which is not a pearl
hence of other wise find the radius of a circle when A= 88/63 leave your answer as a fraction in its simplest form
Answers
Answer:
Step-by-step explanation:
A=πr^2
But A=88/63
88/63=πr^2
88/63π=r^2
√88/63π=r
A circular garden has a diameter of 12 feet. About how much trim is needed to surround the garden by placing trim on the garden's circumference? 38 ft or 48 ft or 144 ft or 432 ft
Answers
Answer:
About 38 feet
Step-by-step explanation:
The formula for a circle's circumference is 2 times pi times r, which is the radius.
Since the diameter is 12, the radius is half the diameter, so the radius is 6.
2 times pi times 6 is about 37.7 feet, or 38 feet.
Hope this helped.
Simplify the number into simplest radical form.
Answers
Answer:
4 sqrt(6)
Step-by-step explanation:
sqrt(96)
We know sqrt(ab) =sqrt(a) sqrt(b)
sqrt(16*6)
sqrt(16) sqrt(6)
4 sqrt(6)
Suppose a company's revenue function is given by R(q) = - q^3 + 220q^2 and its cost function is given by C(q) = 500 + 13q, where q is hundreds of units sold/produced, while R(q) and C(q) are in total dollars of revenue and cost, respectively.
A) Find a simplified expression for the marginal profit function. (Be sure to use the proper variable in your answer.)
MP(q) =
B) How many items (in hundreds) need to be sold to maximize profits? (Round your answer to two decimal places.)
Answers
Answer:
A) MP(q) = -3q² + 440q - 13
B) 146.64 units.
Step-by-step explanation:
The profit function is given by the revenue minus the cost function:
[tex]P(q) = R(q) - C(q)\\P(q) = -q^3+220q^2-500-13q[/tex]
A) The Marginal profit function is the derivate of the profit function as a function of the quantity sold:
[tex]P(q) = -q^3+220q^2-500-13q\\MP(q) = \frac{dP(q)}{dq} \\MP(q)=-3q^2+440q-13[/tex]
B) The value of "q" for which the marginal profit function is zero is the number of items (in hundreds) that maximizes profit:
[tex]MP(q)=0=-3q^2+440q-13\\q=\frac{-440\pm \sqrt{440^2-(4*(-3)*(-13))} }{-6}\\q'=146.64\\q'' = - 0.03[/tex]
Therefore, the only reasonable answer is that 146.64 hundred units must be sold in order to maximize profit.
A linear function and its inverse are given.
y=4x-3
y=1/4x+3/4
Which tables could be used to verify that the functions are inverses of each other? Select two options.
x:1, 3, 5, 7, 9
y:1, 3, 5, 7, 9
x:-23, -15, -3, 1, 13
y:-5, -3, 0, 1, 4
x:-18, -12, 0, 3, 9
y:-24, -18, -6, -3, 3
x:-5, -3, 0, 1, 4
y:-23, -15, -3, 1, 13
x:-24, -18, -6, -3, 3
y:-18, -12, 0, 3, 9
Answers
Answer:
x: -5, -3, 0, 1, 4
y:-23, -15, -3, 1, 13 for the function.
x:-23, -15, -3, 1, 13
y: -5, -3, 0, 1, 4 for the inverse.
Step-by-step explanation:
we know that if we have the function f(x) = y, then the inverse of f(x) (let's call it g(x)) is such that:
g(y) = x.
now we have
y=4x-3
y=(1/4)x+3/4
The only table that works for our first function is:
x: -5, -3, 0, 1, 4
y:-23, -15, -3, 1, 13
You can see this by replacing the values of x and see if the value of y also coincides.
Then, using the fact that the other table must be for the inverse, we should se a table with the same values, but where the values of x and y are interchanged.
The second table is that one:
x:-23, -15, -3, 1, 13
y: -5, -3, 0, 1, 4
Answer: B and D
x:-23, -15, -3, 1, 13
y:-5, -3, 0, 1, 4
x:-5, -3, 0, 1, 4
y:-23, -15, -3, 1, 13
Step-by-step explanation:
The percent, X, of shrinkage on drying for a certain type of plastic clay has an average shrinkage percentage :, where parameter : is unknown. A random sample of 45 specimens from this clay showed an average shrinking percentage of 18.4 and a standard deviation of 2.2. est at 5% level of significance whether the true average shrinkage percentage : is greater than 17.5 and write your conclusion. Report the p-value.
Answers
Answer:
[tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]
The degrees of freedom are given by:
[tex]df=n-1=45-1=44[/tex]
The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4
[tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]
We see that the p value is lower than the significance level so then we can reject the null hypothesis in favor of the alternative.
Step-by-step explanation:
Information given
[tex]\bar X=18.4[/tex] represent the sample mean
[tex]s=2.2[/tex] represent the sample standard deviation
[tex]n=45[/tex] sample size
[tex]\mu_o =17.5[/tex] represent the value to verify
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
We want to test if the true mean is higher than 17.5, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 17.5[/tex]
Alternative hypothesis:[tex]\mu > 17.5[/tex]
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
And replacing we got:
[tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]
The degrees of freedom are given by:
[tex]df=n-1=45-1=44[/tex]
The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4
The p value would be given by:
[tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]
We see that the p value is lower than the significance level so then we can reject the null hypothesis in favor of the alternative.
