Witch step in the scientific method involves making an inference
a. retest by other scientists
b. do background research
c. test with an experiment
d. draw a conclusion

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)

the answer is a for sure mark brainliest i had got this right on usatestprep

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.