Which of the following statements is true

The frequencies refer to the sample data collected from a population of interest when performing a hypothesis test comparing two or more population proportions.

Achlorine atom has 17 protons and 18 neutrons. what is its mass number? what is its atomic number?

You hang a book bag on a spring scale and place the bag on a platform scale so that the platform scale reads 23.7n and the spring scale reads 13.8n. what is the magnitude of the force that earth exerts on the bag?