Learn how running totals differ from rates of change through parcel deliveries....

https://www.mediafire.com/file/wgtscej188dt036/pdf-11118-32695.pdf/file

Learn how running totals differ from rates of change through parcel deliveries. “120 parcels by noon” is a total, while “15 parcels per hour from 10 to 11” is a rate. See how units and time windows clarify what each number means.