TI89: p-value with chi-square cdf and critical value with inverse chi-square

How to get p-value and critical value in the chi square distribution, using chi square cdf function and inverse chi square function. Both functions are in the F5: Distributions menu. Chi square cdf is #8. For inverse chi square, go into the Inverse sub-menu (#2) then choose chi-square (#3). Video is geared toward chi square GOF and two-way tests, but works the same for hypothesis tests and CIs for population variance. See notes below.
Notes:
Chi square cdf (finding p-value): For a chi square GOF test or 2-way test, lower bound is the test statistic, upper bound is a large number like 9999 or E99.
Inverse chi-square (critical value):
1. Always enter area to the left of the chi square critical value you're solving for.
2. For chi square GOF or chi square 2-way test, or right-tail hypothesis test for variance, we're looking for an upper-tail critical value. Alpha is area to the right of the critical value. We enter 1-alpha in the "Area" field.
3. For confidence intervals estimating population variance, or two-tailed hypothesis test for single population variance, we need 2 critical values, one in the upper tail, one in the lower. Lower tail has alpha/2 area to the left of it. Upper tail critical value has 1-(alpha/2) area to the left of it.
4. For left-tailed hypothesis test for variance, alpha is area to the left of the critical value, that's what we enter.