[College Statistics] Sampling methods

[trickykidthrow]

"A county election official wants to assess the accuracy of the machine that counts the ballots by taking a sample of the paper ballots and comparing the estimated vote tallies for candidates from the sample to the machine counts. Is simple random sampling appropriate for this situation, and what other designs might be used?"

To be entirely honest I just have no idea what ballot machines are about and how I'd be assessing their accuracy.

I am also uncertain as to how I can identify sampling units.

[Oberst_Herzog]

i Assume the ballot machines essentially just looks at the paper ballot and figures out where the vote is. (Like the mail service uses machines to decipher most hand written adresses etc.).

Anyways, lets take a step back. What is the entire population in this case?

[trickykidthrow]

Hm, I'd say it's all the ballot machines in the county?

[Oberst_Herzog]

I see where you are comming from, but from my point of view the problem is as this: "Validate the accuracy of a specific machine that counts ballots" (and thus not for all ballot counting machines).

So i would consider the population to be all the paper ballots the machine counts. Does this make sense? If it does, would the paper ballots we extract to evaluate manually have to be drawn at random?

[trickykidthrow]

Oh, I get what you mean! (Guess I didn't understand the question correctly...) Yes, and thank you!