okay the last little bit here at the bottom of page three is a quick review of percentages uh you all met the prerequisite to get in this class because I remember that you doesn't mean that you remember everything you needed to get into the class and percentages are going to come and go and be thrown around like you know them like the back of your hand all semester long so we're going to do a quick review right now and I'm going to go through number three with you and then we're going to see if you can handle number four on your own after I do number three some of you already know how to do it and that's great so when you look at 3A AOL did a survey on their website and asked how much stock do you put in long range weather forecasts and 38 410 people chose to respond for them and in 3A 5 answered a lot how many actual responses were there and answered a lot foreign okay so she took point zero five and multiplied it by 38 410 let's just pause for a second thing why do we multiply do we know why you just do when you multiply this because the percentage is not a whole numbers technically it's the point uh zero five so you would multiply which reduces it so the multiplication reduces it down one of the tricks I like to remember is that in math whenever you see the word of it means multiply so if you want five percent of something that's five percent times that if you want half of something you take half times that number that's one little hint here what else did we do besides multiply something else happens to what I wrote down there yes you uh turn a percentage right turn the percent into a decimal it was five percent but we wrote down 0.05 where'd that come from out of a hundred so five percent really means five out of 100 excellent so you could divide that and it would come out to be 0.05 . what's the shortcut to go from here to here move the decimal over two places to any of that hopefully you remember one or more of those techniques so that's where the 0.05 came from we multiply it by 38 410 what do we get 19 20.5 so there's a half a person floating around somewhere yeah he's worried about a half of us around there somewhere you'll see a problem like this on the on the lab and on the online homework I believe that says find the exact value this is the exact value of this percentage and then the follow-up question is could this be the answer okay the answer is no because the question was how many people answered a lot so what do I do you think around it and we rounded to the nearest whole number because we're talking about people so we rounded because that's a five or more it rounds up to 1921. thank you the 1920 1921 people said a lot in the survey kind of remember a little bit of percentages okay there it's about Part B 's a different question we have 18 053 who said very little or none and we want to know what percent except very little or none about 47 okay I don't know how you got that though yeah um so you take 18. 1853 and then you divide that by 38. [Music] 410 so we take the 18 053 dividing it by the thirty eight thousand four ten how do I know which number goes where it is in the whole this is the whole this is the entire group the large group the whole thing always goes on the bottom and this is just part of it so this is some part out of the hole and so we divide that if you need to use your calculator as a phone today I'm okay with it today when you divide that I want to know exactly what you get without rounding 0.4700078105. how many zeros three seven eight one oh five one oh five and depending on your calculator you might even have four digits after that some calculators can show more we agree with her calculation yeah are we a lot of the simple light to round that so that's a good question on my um so for example this question might have said what percent was that and rounded to two decimal places so the first thing we would do is we would turn it into a percent first and then we would round it so to turn it into a percent I'm going to take the shortcut and he's talking about I'll move the decimal over two places so if I did that this is now a percent and maybe I'll say round to three decimal places when you're on my stat lab doing your homework there's always little blue words underneath the box it tells you where it wants you around when I say three decimal places it means three places after the decimal which is this place right here how do I round to there take the number after and then decide whether to make this go up by one or just leave it alone since this is a five or bigger this one goes up by one so my answer would be 47.001 percent you will always be teleported around and if you're not told that means I don't care rather you're like as long as you round it correctly I'll take it try number four without me can you get it real quick so if you're a whole grade depends on your answer to this question please get today anybody think they got a name I got one a two three only three people think they got this one right four five we're going slowly what's the answer if I don't make your whole grade depend upon in case you're wrong 312.32 about 312 adults yeah yeah why do we have to make it 312. it has to be and it has to be an exact number of adults right yeah because because there's no such thing as like a a half a person that's a matter of a person or something like that and we need to round this one up who was it before running 312.3 32 right so we rounded just left it whatever the way it was yeah