What is the differences between simple random sampling and stratified random sampling?

Must Variables be created before being used? What are the chapters in the Bible that talk about who Jesus is? What is a ordinary number? How can you multpulcation to check if a quotient is coorect? How many cubic yards are in a 22 foot by 22 foot by 3 foot deep hole? How would you add together 19 plus 549 plus 99 plus 999 using Roman numerals in step by step stages? What is the formula for the area of a circle with a diameter? All shapes of polygons? What is 15.522 rounded to the tenth? What an improper fraction with the greatest possible value using each of the digits 5 7 and 9 once. write this mixed number and as a decimal? What is 15 percent of 23.75? Do ten-thirty half past ten and thirty past ten? Is 4860 divisible by 2 3 5 6 9 10? Three consecutive odd counting numbers have the property that the sum of the largest and twice the smallest is 115 what is the middle number? How many wholes are in your body? What are the aspects of pythagores theorem? How many feet does 66 inches equal? What is the mean of 75 82 93 86? What is the answer of 2 numbers multiplied together called? 5 inches equals how many picas?