Sept. 2022 Paper B - Q4 (v) (a)

[Naitik Shah]

For the question mentioned in the subject, I have used a slightly different approach in comparison to the one produced in the ER. The maximum possible marks for the same question is 6. Do let me know the score that I would obtain using my method.

Answer in the Examiner's Report:
Median<- rep(0,5)
Mean<- rep(0,5)
Var<- rep(0,5)
for(i in 1:5)
{ Median<- median(salary.current[job.type==i] )
Mean<- mean(salary.current[job.type ==i] )
Var<- var(salary.current[job.type ==i] ) }

## Median # 9.180 9.285 9.410 10.160 10.030
## Mean # 9.168571 9.280333 9.440000 10.101333 10.119167
## Var # 0.07471261 0.02906540 0.00320000 0.03128381 0.05988106

My Solution: I have individually figured out the values and then copy-pasted the same.

In addition, I also wanted to understand when and in what situations am I supposed to use the FOR loop.

Thanks & Regards.

 

[John Lee]

I'm assuming you just calculated each of them the long-winded way and got the same answers. In which case you would have got the marks - it just would have taken you a lot longer. Hence, a loop would have saved you time.

That's the point of loops - to do the same task repeatedly.

However, the only places where you have to use a loop are clearly indicated in the Core Reading (eg bootstrapping).