Final answer:
The correct type of mail for sending books, catalogs, or merchandise under 70 pounds and 130" in size is Parcel Post. Packages containing books and documents should be weighed in kilograms for practicality. Understanding the weight in pounds and ounces is crucial for calculating postage costs.
Step-by-step explanation:
The type of mail used for mailing items such as books, catalogs, other printed matter, or merchandise not weighing more than 70 pounds and no more than 130" in length or girth is Parcel Post. This service is designed to accommodate the shipping needs for heavier and larger items that do not require the fast delivery times of services like Express Mail.
When Jesse in the mailroom of a large company is tasked with sending out a package containing books and documents, the appropriate metric unit of measurement for him to use to weigh the package is kilograms. This is because milligrams and grams would be too small and cumbersome to use as 10 books and documents would weigh several kilograms, making kilograms the most practical metric unit of mass for this situation.
In terms of calculating postages, it's essential to understand the weight of the package in pounds and ounces, as the post office charges a base rate for the first few ounces and an additional cost for each extra ounce thereafter. For heavier packages, the weight would be converted from kilograms to pounds to determine the exact postage.