In order to obtain a sample of undergraduate students in the world, a simple random sample of 10 countries is selected. from each of the selected countries, 10 colleges or universities are chosen at random. finally, from each of these 100 colleges or universities, a simple random sample of 20 undergraduate students is selected. thus, the final sample consists of 2,000 undergraduates. this is an example of:

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )

Answer a. you’re welcome

If you have a iphone the new measure app can you with that