Answer
Here we have n = 30, df = 29,
Probability 0.75 to the left of t* implies P > 0.25
Using Table C of the book, we have: t* = 0.683
Work Step by Step
Here we have n = 30, df = 29,
Probability 0.75 to the left of t* implies P > 0.25
Using Table C of the book, we have: t* = 0.683