1. In a 1980 census data, Cubans had an average income of $16,368 ( = $3,069; n = 3,895 people), Mexicans had an average of $13,342 (= $9,414; n = 5,726 people), and Puerto Ricans had an average income of $12,587 (= $8,647; n = 5,908 people).Compute the 95% Confidence Intervals (CI's) for all three groups.