A drug manufacturer is developing a vaccine against a particular viral infection. In a preliminary trial, it administered the vaccine to 350 volunteers, 320 of whom developed an immunity to the infection. If the manufacturer can conclude that the vaccine is more than 90% effective, it will proceed to the next stage of development.

1. Define the population and the parameter of interest in this problem
2. Based on the data obtained, should the company proceed to the next stage of development? Clearly state the null and alternative hypotheses in terms of the parameter of interest, calculate the test statistic and the p-value, and state your conclusion in the context of the problem. Use the 5% significance level.