# Computer Science-QA439

## Computer Science-QA439 Online Services

For part c

BetaHat3 = function(units,xy){
if(length(units)==nrow(xy)){ # in the bootstrap part: length(units)==n
ystar = xy[, 2] + xy[units, 3]
m = lm(ystar ~ xy[, 1])
}
else{ # in the jack-knife part: length(units)==n-1
# With the jack-knife (done internally by bcanon),
# we need to use the fitted values and residuals with one element left out as well.
# Otherwise we are trying to add vectors of different length.
ystar = xy[units, 2] + xy[units, 3]
m = lm(ystar ~ xy[units, 1])
}
return(m\$coefficients[2])
}

res_bca3 = bcanon(1:n, BetaHat3, nboot=N, cbind(diabetes\$age, fitted, resid))

PRESS statistic

To ﬁnd the cross-validated residuals and hence the PRESS statistic, we can repeatedly ﬁt the model, leaving out one row at a time, and each time predicting the outcome Y for the data-point that was left out. In the following code, Hospitals[-i,] gives the dataset with the ith row left out. Then predict(modeli, Hospitals[i,]) returns the prediction using the covariates in the ith row. So pred1 is ﬁlled in with the cross-validated predictions ˆ y[i].

You can read more about our case study assignment help services here.

## How it Works

#### How It works ?

Step 1:- Click on Submit your Assignment here or shown in left side corner of every page and fill the quotation form with all the details. In the comment section, please mention Case Id mentioned in end of every Q&A Page. You can also send us your details through our email id support@assignmentconsultancy.com with Case Id in the email body. Case Id is essential to locate your questions so please mentioned that in your email or submit your quotes form comment section.

Step 3:- Once we received your assignments through submit your quotes form or email, we will review the Questions and notify our price through our email id. Kindly ensure that our email id assignmentconsultancy.help@gmail.com and support@assignmentconcultancy.com must not go into your spam folders. We request you to provide your expected budget as it will help us in negotiating with our experts.

Step 4:- Once you agreed with our price, kindly pay by clicking on Pay Now and please ensure that while entering your credit card details for making payment, it must be done correctly and address should be your credit card billing address. You can also request for invoice to our live chat representatives.

Step 5:- Once we received the payment we will notify through our email and will deliver the Q&A solution through mail as per agreed upon deadline.

Step 6:-You can also call us in our phone no. as given in the top of the home page or chat with our customer service representatives by clicking on chat now given in the bottom right corner.

## Case Approach

#### Scientific Methodology

We use best scientific approach to solve case study as recommended and designed by best professors and experts in the World. The approach followed by our experts are given below:

Defining Problem

The first step in solving any case study analysis is to define its problem carefully. In order to do this step, our experts read the case two three times so as to define problem carefully and accurately. This step acts as a base and help in building the structure in next steps.

Structure Definition

The second step is to define structure to solve the case. Different cases has different requirements and so as the structure. Our experts understand this and follow student;s university guidelines to come out with best structure so that student will receive best mark for the same.

Research and Analysis

This is the most important step which actually defines the strength of any case analysis. In order to provide best case analysis, our experts not only refer case materials but also outside materials if required to come out with best analysis for the case.

Conclusion & Recommendations

A weak conclusion or recommendations spoil the entire case analysis. Our expert know this and always provide good chunks of volume for this part so that instructors will see the effort put by students in arriving at solution so as to provide best mark.

## Related Services

n = nrow(Hospitals)
pred1 = vector(length=n)
for(i in 1:n){
modeli = lm(Y ~ X5, Hospitals[-i,])
pred1[i] = predict(modeli, Hospitals[i,])
}
The cross-validated residuals can then be found as
cv res1 = Hospitals\$Y – pred1
Plot both the ordinary residuals and the cross-validated residuals against X5. (If we make a plot with plot(…), we can add another scatter-plot using points(…)). Which is further from 0?
Now calculate the value of the PRESS statistic:,
PRESS1 = sum(cv_res1^2)

Repeat this for the other two models. By looking at the PRESS values which of the three models is best for predicting values of the response variable? Does adding more variables always decrease the value of the PRESS statistic?

Product code: Computer Science-QA439