For the problems which involve writing R code, you will need to submit the R markdown file and

outputted pdf to Canvas. See additional instructions below regrading other files to be submitted. Be

sure to include your name in the header of your RMD program.

$1.$ Create a function that takes a vector of numbers and returns either the median of the vector or

the average value. If the vector contains an odd number of elements, output the median.

Otherwise, if the vector contains an even number of elements, output the average.

a$.$ This function name should be called $`$mean$\_$or$\_$median$`.$ You need to calculate the mean

using the mathematical formula, not using the mean$()$ function.

b$.$ Test your function on the following $3$ vectors:

i$.$ c$(4,15,2,37,182,3876,29,18)$

ii$.$ rep$($c$(23,15,23),15)$

iii. c$(72\mathrm{.}25,281\mathrm{.}3,27361\mathrm{.}2357,926153\mathrm{.}15,(1/3))$

$2.$ Consider the $$computer$$ data. Complete the following:

a$.$ Return the indices of any computer codes that start with A or B followed by any digit.

b$.$ Create a new variable $$NUMCODE$$ that is only the numerical components of each

computer code $($remove all letters$).$

c$.$ Create a new dataset name LETTER$1$ that is only rows where the computer code starts

with a letter.

$3.$ Create a function called $$first$$ that takes a vector and outputs a new vector. For each element of

the vector, if the first character of the string is a digit, in that index of the new vector, assign the

letter D$.$ If the first character of the string is a letter, assign whatever that first letter is to the new

vector index.

a$.$ Test this function on the computer code column of the computer data.