Ok, so in AP Stats we have been using "Table A" to find the probability that a value is "z" standard deviations away from the mean. That is all well and good. However, I was curious as to how "Table A" was generated.
After some search I have found a function on the TI graphing calculators (normalcdf(a,b) that gives the values, where a is -inf when finding prob. for it being less than "z" std dev. away (when counting -2 std dev as less than +1 std dev)
I wanted to create a program on my calculator that would generate these values when the "z" was entered. As the calc had a function in place, this was extremely easy. Additionally I want to be able to enter a prob. and have the calculator determine the "z" value the corresponds.
Unfortunately the two equations I have found that = normalcdf(a,b) are extremely difficult to solve backwards for z (which will be represented by x in the equations)
normalcdf(a,b) will be replaced with P in the equations as well
ok here's a better view of the equations (there should be a closing parenthesis after the (2^k part and before the (k!).