In the 2005-2007 report, they estimated that 30% of all current smokers started smoking before the age of 16. Imagine that we want to verify this estimate. So we randomly select a sample of 100 smokers and calculate the proportion who started smoking before the age of 16. How much error do we expect in the sample proportions if the 30% is correct for the population overall? Use the applet and a give an error based on 2 standard deviations.

Jack lives on a farm and has a large backyard. the area of his rectangular backyard is of a square mile. if the width of the yard is of a mile, what fraction of a mile is the length of the rectangular backyard?

Girardo is using the model below to solve the equation . girardo uses the following steps: step 1 add 4 negative x-tiles to both sides step 2 add 1 negative unit tile to both sides step 3 the solution is which step could be adjusted so that gerardo's final step results in a positive x-value? in step 1, he should have added 4 positive x-tiles to both sides. in step 1, he should have added 3 negative x-tiles to both sides. in step 2, he should have added 4 negative unit tiles to both sides. in step 2, he should have added 1 positive unit tile to both sides.

Which expression demonstrates the use of the commutative property of addition in the first step of simplifying the expression (-1+i)+(21+5i)+0