Bob has an unknown liquid and must determine what it is. he decides to systematically use a number of tests to determine the correct answer. according to piaget, bob has most likely reached the stage of cognitive development.

The Formal Stage

Explanation:

The Stages of cognitive development are as follows:

The Sensorimotor Stage, which is what babies go through, and consists of touchy-feely actions. The name comes from "Sensor" (feelings, nerves) and "Motor" or actions and movements.

The Preoperational Stage is when younger children begin to develop reading and writing skills, along with speech and recognization skills.

The Concrete Operational Stage is where kids start thinking more logically, instead of pretend situations. For example, a boy might understand a dog will play with him if he is calm and collected, instead of when he is rough and loud, thus scaring the dog away.

The Formal Operational Stage is when older kids start to make more logical conclusions through running tests and collecting data in a organbized way. This is when the child begins thinking like an adult.

Based on the information given, Bob best fits the 4th stage, Formal, because he chooses to do systematic tests to find what the liquid is.

for many centuries there were important factors which the economies of the muslim empires developed increasingly. they applied economic procedures in production, investment, finance, taxation and property. they used to tax certain goods (for example: harvest), they charged interest on money lent, they signed contracts with merchants; they relied on a common currency, and they used checks as well as promissory notes. with the money collected by means of taxation, the government provided the needy with an income. in addition, trading networks covered huge distances, so far regions started to have contact and exchange goods. this trade network covered areas of asia, africa and europe.