Which type of study best describes the following research most likely to be done?

a teacher wants to know how fast all her students for a particular period can complete a multiplication quiz to check their mental math abilities. so, all of her students are tested on a computer and the time of each and every student is recorded.

group of answer choices

experimental study

observational study

simulation study

census

sampling

Pls! does anybody know a shortcut for answering these types of questions in the future?

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is approximately normally distributed with a mean of 1252 chips and standard deviation 129 chips. (a) what is the probability that a randomly selected bag contains between 1100 and 1500 chocolate chips, inclusive? (b) what is the probability that a randomly selected bag contains fewer than 1125 chocolate chips? (c) what proportion of bags contains more than 1225 chocolate chips? (d) what is the percentile rank of a bag that contains 1425 chocolate chips?

Jennifer graphs the function f(x)=x squared. then she graphs the function f(x-3). how does the graph f(x-3) differ from the graph of f(x)