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?

Juliana says that she can use the patterns of equivalent ratios in the multiplication table below to write an infinite number of ratios that are equivalent to 6: 10. which statement explains whether juliana is correct? she is correct because she can multiply 6 and 10 by any number to form an equivalent ratio. she is correct because 6: 10 can be written as 1: 2 and there are an infinite number of ratios for 1: 2. she is not correct because the multiplication table does not include multiples of 10. she is not correct because 6: 10 is equivalent to 3: 5 and there are only 9 ratios in the multiplication table that are equivalent to 3: 5.