A study was conducted to compare the mean numbers of police emergency calls per 8-hour shift in two districts of Los Angeles. Samples of 100 8-hour shifts were randomly selected from the police records for each of the two districts, and the number of emergency calls was recorded for each shift. The sample statistics are listed below. Find a 90% confidence interval for the difference in the mean numbers of police emergency calls per shift between the two districts of the city. Round your answer to four decimal places and interpret the interval.