DESCRIPTION

Please keep in mind the OMSI rules.

Save your files often.

Submit each answer individually and make sure you receive the notification of successful submission.

Don't wait till the last moment to submit all answers, as there might be network traffic in the last 5 minutes causing unexpected delay and failure.  

Remember that clicking CopyQtoA will copy the entire question box to the answer box.

In questions involving code which will PARTIALLY be given to you in the question specs, you may need to add new lines. 
There may not be information given as to where the lines should be inserted. 

MAKE SURE TO RUN THE R CODE ANSWER IN PROBLEMS THAT INVOLVE R CODE!

QUESTION

(Text answer - 25 pts)  The R functions plot(), print() and summary() are
examples of _________________ functions.


QUESTION -ext .R -run 'Rscript ./omsi_answer2.R'

(R code answer - 25 pts)  Consider the toy example, p.209.  Let T = X_1 X_2.
Find ET.  (Note:  There is a short cut.)



QUESTION -ext .R -run 'Rscript ./omsi_answer3.R'

(R code answer - 25 pts)  Say we have a random sample, X_i, i = 1,2,...,n
from some population in which X has unknown density f_X.  We are
interested in the population mean mu, and will use W = the sample mean
("X-bar") as our estimator.  Then |W - mu| is our estimation error, and
we may be interested in E(|W - mu|).  Use simulation to evaluate that in
the case of f_X being an exponential distribution with mean 2.0.

sim <- function(n,nreps) {
 

}

print(sim(1000,10000))


QUESTION  -ext .R -run 'Rscript ./omsi_answer4.R'

(R code answer - 25 pts)  Write a function that does k-Nearest Neighbor
prediction for a single predictor.

[KNN functions from stat/ML libraries are NOT allowed. You MAY use sort() or order() if you wish]

kNear <- function(x,y,k,newx)  # x,y are vector, newx a "scalar"
{ 


   predValue <- 
   return(predValue)
}

x <- c(5,12,13,8.88)
y <- c(22,11,5.5,12.12)
newx <- 13.2)
print(kNear(x,y,3,newx)