Answer
a) The claim is not valid.
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 different to $\frac{65}{455}=0.1429$, so we know $H_0:μ=0.1429$ and $H1:μ\lt0.1429$. We now use a Ti-84 calculator. To solve, go to "Stat," then "Tests," and then select "Stats." Doing this, we can find that the critical value and use a z-table calculator to find that $p=\gt0.05$, hence the claim is not valid.
b) We use a ti-84 calculator 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 can find that the confidence interval goes through $0$, so the claim cannot be proved to be valid, because there is uncertainty.
c) The results show that men and women do have similar success rates when challenging calls.
