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Okay sy match members ron to statistical measures and we're

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going to live inside this normal table for a lot

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of it So look at this thing right here Normal

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table What is the probability that corresponds to a z

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score of point O nine Well we've got a z

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scored we need the probability we're trying to find the

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probability of getting that z score or score less than

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that z score Let's according to question here to remember

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that a z score is just how far we are

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away from the mean this thing in units of standard

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deviation like the sigma things down here a standard normal

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curve has been studied so closely that we can plop

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ourselves down at an easy score on the x axis

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and immediately determine the area under the curve to the

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left of that value which is the same as the

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probability of a z score less than or equal to

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ours for any z score we can imagine so let's

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think about this We'll need a standard normal table right

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here Luckily this table will tell us the probability of

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getting the z score we want because it's a left

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area ze table So you have to check that if

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this were a table that shows the area to the

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right of a z score we have to subtract the

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value we get from the table from one right one

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is one hundred percent or entire area there under the

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curve So r z scores point o nine We'll need

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to zip line down to the second page where we

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see the zero point zero row there right at the

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top Then we crab crawl across to the column headed

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by point Oh nine i think in a cell at

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the intersection of that roman column is our probability which

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is what is this point Five three five eight six

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Alright we'll round that off a bit and it gives

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us a probability of five three five nine Well we

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must have looked in a completely different part of the

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table to get all the other answers as none of

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them are at the intersection of zero point to a

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row Okay so the answer is C five three five 00:01:57.842 --> [endTime] nine that's it were statistically shmoop

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