In a study in the early 1990s, 170 of 2,673 individuals (6.4%) reported having two or more sexual partners in the prior 12 months. suppose an earlier study (completed in the 1970s) suggested that the prevalence of this attribute in the population was 7.5%. is the observed proportion significantly different from the prior prevalence? use a two-sided alternative and show all steps. create and interpret a confidence interval for the prevalence.