Answer
a. The claim is not accepted.
b. The claim is not shown to be valid.
c. The rate of males who are left handed cannot be shown to be different than the rate of left-handed females.
Work Step by Step
a. We want to see if the mean is less than $\frac{65}{455}=.1429$, so we know $H_0: \mu = .1429$ and $H_1: \mu \lt .1429$. We now use a Ti-84 calculator. To solve, go to "Stat," then "Tests," and then select "Stats." Doing this, we find that the critical value and use a z-table calculator to find that p is more than .05, so the claim is not valid.
b. We use a ti-84 to find the confidence interval. To do this, we press “Stat” and then select “Tests.” Next, we select “2-PropZInt” to conduct the test. Doing this, we find that the confidence interval goes through 0, so the claim cannot be proved to be valid, for there is uncertainty.
c. The results show that men and women do have similar success rates when challenging calls.
