Here's another article from the Palestine Post that shows how Arabs benefited from Jewish investment in Palestine. The issue was October 10, 1933. Even if one argues that the source is biased, the figures are precise.
It shows that the number of dunams of land planted by Arabs skyrocketed, unemployment dropped sharply, and that the major beneficiaries of agriculture tax were Arabs.
The editorial in that issue expands upon the findings and compares them to the awful economic conditions in Palestine's Arab neighbors:
This continued to be the case until the 1936-39 Arab "revolt," meant as a strike to cripple the Jewish economy, instead it only retarded the Arab economy in Palestine. As we've seen countless times since, the Arab leaders directly caused their own people to suffer in their vain pursuit of destroying the Jewish national movement.