Z SCORES AREAS NORMAL DIST

Question

Find the area under the normal curve, to the left of z = 2.09

Answer 1

For this question, we need either a graphing calculator or a z-score to percentile table. If using a table, simply find the z-score and write down the corresponding decimal. On my table, I get 0.9817. If you want to use a TI-84 calculator to solve this, you can use the following steps:

2nd --> vars --> normalcdf

For the lower bound, enter -99999 to simulate -infinity, since we want ALL of the area of the curve below z = 2.09.

For the upper bound, put 2.09

For mu (the mean), put 0, and for sigma (standard deviation), put 1, since we assume a standard normal curve when using z-scores.

Then paste and hit enter.