What problems did muckrakers expose and what effects on their work have on progressive reform?

Muckrakers exposed  a diversity of social and economic problems including political corruption, child labor, and work  safety issue. Their work increased support for progressivism, which, helped in ushering reform that ended child labor, reduced workweek, and improved the lives of the poor.

They were journalists who exposed the problems with monopolies in oil companies, meat shops and brothles. These were social problems that they exposed to the world and also created FDA for this reason so make sure the health of these places were on spot.

Explanation:

there were abundant sources of fuel nearby

a. theta waves. this is because the person is in a light sleep which means the brain waves would show these kind of waves.