Answer
a) The claim is valid.
b) The claim is valid.
c) Women with the single bill were less likely to spend all of the money
Work Step by Step
a) We want to see if the mean is different to $\frac{68}{75}=0.9067$, so we know $H_0:μ=0.9067$ and $H1:μ\lt0.9067$. 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 $p=\lt0.05$, hence the claim is 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 is completely negative, meaning that they are less likely to spend all of the money when given larger bills and meaning that the claim is valid.
c) The results show that, when given one larger bill, women are less likely to spend all of the money.