A pet store surveyed three groups of 5 customers to find out how many pets the customers owned. The table shows the results of t
he three samples. Survey Number of Pets Group 1 {1, 3, 2, 2, 3} Group 2 {6, 5, 7, 3, 4} Group 3 {2, 3, 1, 1, 4} Identify surveys that are likely biased. Based on the unbiased surveys, estimate the mean number of pets that the customers own. Enter your answer in the box. Round to the nearest whole number.