Identify the type of sampling used (random, systematic, convenience, stratified, or cluster sampling) in the situation described below. a researcher selects every 139 th social security number and surveys the corresponding person. nothing nothing nothing which type of sampling did the researcher use?

How did trade contribute to the spread of the plague in the 1300s? trading vessels from the americas brought the plague to london, where it spread across europe. trading caravans from mongolia brought the plague to rome, where it spread across europe. trading caravans from russia brought the plague to barcelona, where it spread across europe. trading vessels from china brought the plague to sicily, where it spread across europe.