Prior to an influenza season subjects were randomly assigned to receive either a flu vaccine or a placebo. During that season there were 28 cases of the flu among 813 vaccine recipients and 35 cases of the flu among the 325 subjects who were given the placebo. Do these data indicate that the vaccine was effective? Conduct an appropriate Chi-Square test using a directional alternative with α" style="box-sizing: border-box; -webkit-tap-highlight-color: rgba(0, 0, 0, 0); border: 0px; max-width: 100%; height: auto; display: inline; vertical-align: middle; line-height: inherit; max-height: 31.25rem;">= 0.05.

a). List hypotheses

b). Perform the test

c). Conclusion based on the test result.