The principal of a small school needs a sample of 20 students, so she goes to the cafeteria and asks every fifth student in line to answer a survey. what kind of sampling is this?

a. simple random sampling
b. stratified random sampling
c. systematic sampling
d. convenience sampling

Which statement is true? the given sides and angles cannot be used to show similarity by either the sss or sas similarity theorems. the given sides and angles can be used to show similarity by the sss similarity theorem only. the given sides and angles can be used to show similarity by the sas similarity theorem only. the given sides and angles can be used to show similarity by both the sss and sas similarity theorems.

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

Satchi found a used bookstore that sells pre-owned dvds and cds. dvds cost $9 each, and cds cost $7 each. satchi can spend no more than $45.