Question 1153866: Use the standard normal table to find the z-score that corresponds to the given percentile. If the area is not in the table, use the entry closest to the area. If the area is halfway between two entries, use the z-score halfway between the corresponding z-scores. If convenient, use technology to find the z-score.
Upper P 80
Answer by Edwin McCravy(20063)   (Show Source):
You can put this solution on YOUR website!
There are two kinds of tables in use today.
If your table has negative values in the z-column, then look through
the body of the table till you find the two values which 0.80 is between,
which are 0.7996 and 0.8023. We see that 0.8 is closer to 0.7996, so
use the z-score 0.84 [with 0.8 in the left column and 0.04 heading the
column that 0.7996 in under.
Answer 0.84
If there are no negative values in your table, then first subtract 0.5
from 0.80 getting 0.30. Then look through the body of the table till
you find the two values which 0.30 is between, which are 0.2996 and 0.3023.
We see that 0.30 is closer to 0.2996, so use the z-score 0.84 [with 0.8 in
the left column and 0.04 heading the column that 0.2996 in under.
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With TI-83 or 84
press 2ND VARS 3
If you have a newer version of the calculator,
(area: .80, m:0, s:1, tail LEFT) [Paste]
In any case, make sure you see one of these on the main screen:
invNorm(0.80) or invNorm(0.80,0,1) or invNorm(0.80,0,1,LEFT)
press ENTER
0.8416212335
Edwin
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