A restaurant owner wants to determine the effectiveness of his servers. The owner places a survey regarding the servers' effectiveness with randomly selected customer bills. What is the sample?.

Answer60 minutes;

It would have to be c or d

Which of the following is an example of an opposing signal? no examplthates given.   i would say, that traffic lights in a city at major intersections direct the flow of traffic in opposite directions so would be an example.also, stop signs on either side of the same street would be an example. at a train crossing, the light for allowing car traffic in opposite directions or not would be another example.