Find the critical value that corresponds to a 90% confidence level.I know that the answer is 1.645. But i tried to look it up on the Z score table, but i couldn't figure out how to read it. I did the following: 0.9+1 = 1.90.I then look at the left side for 1.9 and on the top i search for 0.0, the number that is stated there is 0.9713. Which isnt true.Can someone explain me please how to use the Z-table

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Find the critical value that corresponds to a 90% confidence level.I know that the answer is 1.645. But i tried to look it up on the Z score table, but i couldn&#039;t figure out how to read it. I did the following: 0.9+1 = 1.90.I then look at the left side for 1.9 and on the top i search for 0.0, the number that is stated there is 0.9713. Which isnt true.Can someone explain me please how to use the Z-table

impire7vw · Accepted Answer

Z-score tables show cumulative probability up to the given value of the statistic Z. I.e., they drop the right tail but not the left tail. If you want to have 90% in your retained range and drop both tails (which you do), you need to figure out how much you&#039;re dropping from each tail.Since in total you&#039;re dropping 10% and the distribution is left-right symmetric, you want to drop 5% from each tail. To find where the right limit is, find 0.95 in the table and read out the matching Z-score from the column and row. This is the right end-point (cutting off a 5% tail to the right). By symmetry, minus that is the left end-point (cutting off a 5% tail to the left). What does that leave? 90% in the middle.

Find the critical value that corresponds to a 90% confidence level. I know that the answer is 1.64

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