2 AP Stat Probability Questions

Test Preparation AP Test Preparation
1

<p>A fair coin (one for which both the probability of heads and the probability of tails are 0.5) is tossed 60 times. The probability that less than 1/3 of the tosses are heads is ____?</p>

<p>What I Did</p>

<p>binomcdf(60,0.5,19)=0.003, but the answer key says 0.0043</p>

<p>A college basketball player makes 80% of his free throws. Over the course of the season he will attempt 100 free throws. Assuming free throw attempts are independent, what is the probability that he makes at least 90 of these attempts?</p>

<p>What I Did
1 - binomcdf(100,0.8,89)=0.0057, but the answer key says 0.0062</p>

<p>Thanks in advance!</p>

2

<p>I would post this in that official stat thread. That’s where you will find the most help, from other people taking the exam and ppl who have taking the test in past years.</p>