SOLUTION: Suppose z is a standard normal random variable. Find the value of z subscript italic alpha divided by 2 end subscript such that P left parenthesis minus z subscript alpha divided b
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-> SOLUTION: Suppose z is a standard normal random variable. Find the value of z subscript italic alpha divided by 2 end subscript such that P left parenthesis minus z subscript alpha divided b
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Question 1108219: Suppose z is a standard normal random variable. Find the value of z subscript italic alpha divided by 2 end subscript such that P left parenthesis minus z subscript alpha divided by 2 end subscript less than z less than space z subscript italic alpha divided by 2 end subscript right parenthesis equal .80 Answer by Theo(13342) (Show Source):
i think what you're looking for is the interval between the two end points, where the area in between is .8.
.8 in between means .2 outside which is divided by 2 to get .10 on each end.
.10 would be your alpha / 2.
to find the area with .8 in between, you would find the z-score for an area of.9 to the left of it and the z-score for an area of .1 to the left of it.
the area between the z-scores would be the area in between.
the z-score with an area to the left of it equal to .9 would be z = 1.281551567.
the z-score with an area to the left of it it equal to .1 would be z = -1.281551567.
the area in between is .8.
a picture of what what would look like is shown below.
i'm assuming you are able to find the area to the left of a z-score and to find the z-score with a specified area to the left of it.
if you need help with that, let me know and i'll give you some more detailed instructions.
the calculator with the picture can also be used, but it will spoil you.
bet you learn how to do it the hard way first, so you have that up your sleeve in case you need it.
