A geology teacher takes her class on an annual field trip to analyze rock samples. They use randomized sets of coordinates to select samples from two regions.
Suppose they examine a sample of 70 rocks from region A, which is composed of 15% igneous rock. Then they
examine a sample of 60 rocks from region B, which is composed of 20% igneous rock. Then they look at the
difference between the sample proportions (PA - B).
What are the mean and standard deviation of the sampling distribution of pA - PB?

B

Step-by-step explanation:

It’s obvious

the reason why your question keeps getting deleted because this is not a school related question : )

i will answer your question though.

i never tried church's

answer: since the question is talking about growth you have to use the growth formula which is inital amount (1 + growth)^time

step-by-step explanation:

the intial amount is 1200, the growth is 4.8, and the time is 7. plug those numbers into the equation, also i think you have to change 4.8 into a percent. but, i have forgotton how to do that. if this is a online class go on to the lesson.