Rhode Island is about 350 times smaller than Tanzania.

Tanzania is approximately 947,300 sq km, while Rhode Island is approximately 2,706 sq km, making Rhode Island 0.29% the size of Tanzania. Meanwhile, the population of Tanzania is ~63.9 million people (62.8 million fewer people live in Rhode Island).
Tip: This to-scale comparison of Tanzania vs. Rhode Island uses the Mercator projection, which distorts the size of regions near the poles.