Answer:
F test
Step-by-step explanation:
Given that we want to study the average weight of children in the US. We collect a random sample of 345 first graders in three different US states
Since there are three samples representing three populations to check whether they have same average weight we have to use F test.
Two sample t test is wrong because here there are three samples.
Paired t test is done for the same item subject to two different tratments
Z test is done for comparing of a mean with population mean or proportion if the population standard deviation is known.
Hence here since the number of groups are more than two, only F test is best suited to determine whether there is a difference in the average student weight among the three states
