Gallup conducted a national survey of 1008 American adults, asking "As you may know, as part of its efforts to investigate terrorism, a federal government agency obtained records from larger U.S. telephone and Internet companies in order to compile telephone call logs and Internet communications. Based on what you have heard or read about the program, would you say that you approve or disapprove of this government program?" Of those surveyed, 534 said they disapprove.

a. Determine and interpret the sample proportion.

b. At the 5% significance level, do the data provide sufficient evidence to conclude that a majority (more than 50%) of American adults disapprove of this government surveillance program?