A nurse orientation program director is examining data about nurses in their first year of practice at her hospital. Use the table below to answer the following question. Number of months of experience Number of medication errors made Cumulative Frequency of Medication Errors 1-3 6 6 4-6 17 23 7-9 12 35 10-12 10 45 What percentage of the medication errors were made in the first nine months of practice?