Which statistical test compares more than 2 sets of data and finds the difference between the data and the expected values

An object weighs 40n in air , weighs 20n when submerged jn water and 30n submerged in a liquid of unknown density .what is the density of the liquid?

Historical vs today's presidents (compare)

Now , use your research to decide what business is the best choice for this community. explain your choice in two to three sentences, using factual evidence to support your claim.