Questions
Using the mtcars dataset, answer the following questions: Fill in the following table: Variable Correlation with...

Using the mtcars dataset, answer the following questions:

Fill in the following table:

Variable

Correlation with mpg

cyl

-0.85216

disp

-0.84755

hp

-0.77617

drat

0.681172

wt

-0.86766

qsec

0.418684

vs

0.664039

am

0.599832

gear

0.480285

carb

-0.55093

mpg cyl disp hp drat wt qsec vs am gear carb
Mazda RX4 21 6 160 110 3.9 2.62 16.46 0 1 4 4
Mazda RX4 Wag 21 6 160 110 3.9 2.875 17.02 0 1 4 4
Datsun 710 22.8 4 108 93 3.85 2.32 18.61 1 1 4 1
Hornet 4 Drive 21.4 6 258 110 3.08 3.215 19.44 1 0 3 1
Hornet Sportabout 18.7 8 360 175 3.15 3.44 17.02 0 0 3 2
Valiant 18.1 6 225 105 2.76 3.46 20.22 1 0 3 1
Duster 360 14.3 8 360 245 3.21 3.57 15.84 0 0 3 4
Merc 240D 24.4 4 146.7 62 3.69 3.19 20 1 0 4 2
Merc 230 22.8 4 140.8 95 3.92 3.15 22.9 1 0 4 2
Merc 280 19.2 6 167.6 123 3.92 3.44 18.3 1 0 4 4
Merc 280C 17.8 6 167.6 123 3.92 3.44 18.9 1 0 4 4
Merc 450SE 16.4 8 275.8 180 3.07 4.07 17.4 0 0 3 3
Merc 450SL 17.3 8 275.8 180 3.07 3.73 17.6 0 0 3 3
Merc 450SLC 15.2 8 275.8 180 3.07 3.78 18 0 0 3 3
Cadillac Fleetwood 10.4 8 472 205 2.93 5.25 17.98 0 0 3 4
Lincoln Continental 10.4 8 460 215 3 5.424 17.82 0 0 3 4
Chrysler Imperial 14.7 8 440 230 3.23 5.345 17.42 0 0 3 4
Fiat 128 32.4 4 78.7 66 4.08 2.2 19.47 1 1 4 1
Honda Civic 30.4 4 75.7 52 4.93 1.615 18.52 1 1 4 2
Toyota Corolla 33.9 4 71.1 65 4.22 1.835 19.9 1 1 4 1
Toyota Corona 21.5 4 120.1 97 3.7 2.465 20.01 1 0 3 1
Dodge Challenger 15.5 8 318 150 2.76 3.52 16.87 0 0 3 2
AMC Javelin 15.2 8 304 150 3.15 3.435 17.3 0 0 3 2
Camaro Z28 13.3 8 350 245 3.73 3.84 15.41 0 0 3 4
Pontiac Firebird 19.2 8 400 175 3.08 3.845 17.05 0 0 3 2
Fiat X1-9 27.3 4 79 66 4.08 1.935 18.9 1 1 4 1
Porsche 914-2 26 4 120.3 91 4.43 2.14 16.7 0 1 5 2
Lotus Europa 30.4 4 95.1 113 3.77 1.513 16.9 1 1 5 2
Ford Pantera L 15.8 8 351 264 4.22 3.17 14.5 0 1 5 4
Ferrari Dino 19.7 6 145 175 3.62 2.77 15.5 0 1 5 6
Maserati Bora 15 8 301 335 3.54 3.57 14.6 0 1 5 8
Volvo 142E 21.4 4 121 109 4.11 2.78 18.6 1 1 4 2
correlation -0.85216 -0.84755 -0.77617 0.681172 -0.86766 0.418684 0.664039 0.599832 0.480285 -0.55093

Which of the variables is the best predictor of mpg? Justify your answer using the correlation coefficient and a scatterplot.

Fit a regression model based on your answer to question 2. Write your model below.

Is the slope significant? Justify your answer.

Interpret the slope of your regression model.

Interpret the r2 value.

Do you believe your model is a good model for predicting mpg? Justify your answer.

In: Math

1. 100,000 Massachusetts adults were randomly sampled with two factors recorded: whether or not the individual...

1. 100,000 Massachusetts adults were randomly sampled with two factors recorded: whether or not the individual

had diabetes, and whether or not the person ate Kale. The following gives a table of the results.

Diabetes No Diabetes

Kale: 796 9187

No Kale: 9900 80117

(a) We write p(Diabetes | Kale) for the probability that a Massachusetts adult who eats kale has diabetes.

Either give a value for p(Diabetes | Kale) or explain why it cannot be computed.

(b) We write ^p(Diabetes | Kale) for the proportion of Kale-eating members of our sample above that had

diabetes. Either give a value for ^p(Diabetes | Kale) or explain why it cannot be computed.

(c) Give 95% confidence intervals for the probability of having diabetes for both the kale-eating and non-kale-

eating members of our Massachusetts adults.

(d) Can you conclude that the kale-eaters are less likely to have diabetes? Explain your reasoning.

(e) Can you conclude that kale consumption causes a lower diabetes rate in this population? Explain your

reasoning.

(f) Come up with a possible theory that explains why kale-eaters have a lower rate of diabetes, but does not

assume that kale causes the lower rate.

In: Math

I have no strong background in Probability, please, present to me an easy to understand solution...

I have no strong background in Probability, please, present to me an easy to understand solution to this problem with detail explanation. Thank you.

An urn contains three white, six red, and five black balls. Six of these balls are randomly selected from the urn. Let X and Y denote
respectively the number of white and black balls selected. Compute the conditional probability mass function of X given that Y = 3. Also compute E[X|Y = 1]

In: Math

Describe and discuss at least 1 other business scenario in which you believe Chi-square testing would...

Describe and discuss at least 1 other business scenario in which you believe Chi-square testing would be helpful to a company.

Use the following data to conduct a Chi-square test for each region of the company

Region Expected

Actual

Southeast

Defined

100 98

Open

100 104
Northeast

Defined

150 188

Open

150 214
Midwest

Defined

125 120

Open

125 108
Pacific

Defined

200 205

Open

200 278

In: Math

For 300 trading​ days, the daily closing price of a stock​ (in $) is well modeled...

For 300 trading​ days, the daily closing price of a stock​ (in $) is well modeled by a Normal model with mean $195.89 and standard deviation ​$7.18

According to this​ model, what cutoff value of price would separate the

​a) lowest 15% of the​ days?

​b) highest 0.61​%?

​c) middle 80​%?

​d) highest 50​%?

c) Select the correct answer below and fill in the answer​ box(es) within your choice.

A.The cutoff points are _________ and _________.

​(Use ascending order. Round to two decimal places as​ needed.)

B.The cutoff point is _________. ​(Round to two decimal places as​ needed.)

In: Math

A concrete service owns 3 mixer trucks to deliver concrete to work sites in a local...

A concrete service owns 3 mixer trucks to deliver concrete to work sites in a local area. For each order, a truck is loaded and weighed with mix at the single station for the order. Then the truck makes the delivery and returns for the next load. Assume that there is always an order for each truck. The delivery times are 15 minutes plus an exponential amount with mean 30 minutes and load/weigh times are 8 minutes. This is a variation on the single server queue with a fixed population of trucks. Trucks are served at the loader and return to it as arrivals following their delivery. Simulate this system by hand for 3 hours simulated time and report on the number of deliveries completed. The trucks begin empty, ready to be loaded.

In: Math

1. A $1 scratch off lotto ticket will be a winner one out of 10 times....

1. A $1 scratch off lotto ticket will be a winner one out of 10 times. Out of a shipment of n = 200 lotto tickets, using the Poisson distributions in each case (for a, b and c), find the probability for the lotto tickets that there are: a. somewhere between 75 and 95 prizes. b. somewhere between 15 and 25 prizes. c. more than 50 prizes d.If a customer keeps buying tickets till she finds a winner, find the probability that her 10th ticket will be a winner.

In: Math

Each of three barrels from a manufacturing line are classified as either above (a) or below...

Each of three barrels from a manufacturing line are classified as either above (a) or below (b) the target weight. Provide the ordered sample space.

In: Math

An online poll at a popular web site asked the following: A nationwide ban of the...

  1. An online poll at a popular web site asked the following:

    A nationwide ban of the diet supplement ephedra went into effect recently. The herbal stimulant has been linked to 155 deaths and many more heart attacks and strokes. Ephedra manufacturer NVE Pharmaceuticals, claiming that the FDA lacked proof that ephedra is dangerous if used as directed, was denied a temporary restraining order on the ban yesterday by a federal judge. Do you think that ephedra should continue to be banned nationwide?

    65% of the 17,303 respondents said “yes.” Comment on each of the following statements about this poll in one or two complete sentences.

    1. (a) With a sample size that large, we can be pretty certain we know the true proportion of Americans who think ephedra should be banned.

    2. (b) The wording of the question is clearly very biased.

    3. (c) The sampling frame is all Internet users.

    4. (d) This is a voluntary response survey, so the results can’t be reliably generalized to any population of interest.

In: Math

Describe how and why you should partition your data when using classification techniques like k-nearest neighbors...

Describe how and why you should partition your data when using classification techniques like k-nearest neighbors and logistic regression.

In: Math

Eight pawns are placed at random on an 8 × 8 chessboard, with all configurations equally...

Eight pawns are placed at random on an 8 × 8 chessboard, with all configurations equally likely. What is the probability of each of these events:

1. The pawns are in a straight line. (Don’t forget the diagonals!)

2. All the pawns occupy white squares.

3. No two pawns share the same row.

4. Now two pawns share the same row or the same column.

In: Math

7. A student measures the mass percent chloride in their unknown four times by each of...

7. A student measures the mass percent chloride in their unknown four times by each of two methods. (a) Find the mean, standard deviation, and 95% confidence limit for each method. (b) Determine if each method’s result is “significantly” different from the expected value of 48.86% Chloride. (c) Use the F test to decide whether the standard deviations are “significantly” different. (d) Use the t test to decide whether the means are different from one another at the 95% confidence level.

Method Replicate Measurements

A 47.62% 47.91% 47.83% 47.79% 48.01%

B 47.11% 49.63% 48.72% 49.17% 47.99%

In: Math

A manufacturer of television sets is interested in the effect on tube conductivity of four different...

A manufacturer of television sets is interested in the effect on tube conductivity of four different types of coating for color picture tubes. A completely randomized experiment is conducted, and the following conductivity data are obtained:

Coating type

Conductivity

1

143

141

150

146

2

152

149

137

143

3

134

136

132

127

4

129

127

132

129

a) Is there a difference in conductivity due to a coating type? Use α= 0.05.

b) Estimate the overall mean and the treatment effects.

c) Calculate a confidence interval with 95% for the average coating type 4 and calculate the confidence interval with 99% for the difference between the average coating types 1 and 4.

d) Test all pairs of means using the Fisher LSD method with α= 0.05.

e) Use the graphical method discussed in section 3-5.3 to compare the means. What is the type of coating which produces the highest conductivity?

f) Assuming that coating type 4 is currently being used, what would you recommend to manufacturer? It wants to minimize conductivity.

g) Analyze the residuals and draw conclusions about the adequacy of the model.

In: Math

Let t 0 be a specific value of t. Use the table of critical values of...

Let t 0 be a specific value of t. Use the table of critical values of t below to find t 0 dash values such that following statements are true. a. Upper P left parenthesis t greater than or equals t 0 right parenthesisequals​.025, where dfequals11 b. Upper P left parenthesis t greater than or equals t 0 right parenthesisequals​.01, where dfequals18 c. Upper P left parenthesis t less than or equals t 0 right parenthesisequals​.005, where dfequals7 d. Upper P left parenthesis t less than or equals t 0 right parenthesisequals​.05, where dfequals14 LOADING... Click the icon to view the table of critical values of t.

In: Math

7. Two fair six sided dice are rolled. (i) What is the probability that the sum...

7. Two fair six sided dice are rolled.

(i) What is the probability that the sum of the two results is 6?
(ii) What is the probability that the larger value of the two results is 4?

(iii) What is the probability that the both results are at most 4?
(iv) What is the probability that the number 3 appears at least once?

In: Math