6) A shortage of candidates has required school districts to pay higher salaries to attract and retain school district superintendents. The following data shows the annual base salary ($1000s) for superintendents in 20 districts in the greater NY area: 187 184 174 185 175 172 202 197 165 208 215 164 162 172 182 156 172 175 170 183 Construct a 5-column relative frequency distribution using 7 classes. The district wants to keep superintendent salaries less than $180,000. Your frequency distribution must reflect this.