User`s guide

Statistical Calculations132
Inverse of Student’s t Probability Lower Tail
If you know the lower tail probability, P, and you want to calculate t, enter the degrees of
freedom (df
1
), followed by Æ, then P. Press ]oIto calculate t.
Figure 14
Example
A hypothesis test requires a critical t-value from the Student’s T distribution with 26 degrees
of freedom. Find the t-value for a lower tail probability of .05.
Table 12-22 Example calculating the t-value (lower tail)
Keys Display Description
GS]oI7:V4
-1.705618 Enter degrees of freedom
and the probability, and
calculates the lower tail
t- value.
or, using Æ:
GSÆ7:V]oI
Returns the same results.
Figure 15 Figure 16