On a science quiz, David got 45 out of 70 items correct. What is the empirical probability of his incorrrect responses? Write your answer in the simplest form of a fraction.
To find the probability of David's incorrect responses, we need to subtract the number of correct responses from the total number of items on the quiz:
Total items on the quiz = 70 items
Number of correct responses = 45 items
Number of incorrect responses = 70 - 45 = 25
Now, we can find the empirical probability of his incorrect responses by dividing the number of incorrect responses by the total number of items:
Empirical probability of incorrect responses = Number of incorrect responses / Total number of items
Empirical probability of incorrect responses = 25 / 70
Therefore, the empirical probability of David's incorrect responses is 25/70, which simplifies to 5/14.