Identify at least three examples of the power muckrakers of the late nineteenth century and early twentieth centuries

As a result of the efforts of muckrakers, child labor laws were rewritten, food, and medicine were protected for consumers, rules for fair business practices, and the reduction if possible of political corruption.

hopefully this helps

Muckrakers were reformist American journalists who denounced corrupt institutions and leaders and played a highly visible role during the Progressive Era period (1890s-1920s).

The article Tweed Days in St. Louis (1902) was written by Steffens and Wetmore and was called the first muckraking article. In it, Major Ziegenhein and the city council were denounced for corruption, claiming they were stealing the public budget and getting bribes to approve regulations. The prominence of the article helped lawyer Joseph Folk to lead an investigation of the corrupt political ring in St. Louis. Upton Sinclair published The Jungle in 1906, which revealed conditions in the meat packing industry in the United States and was a major factor in the establishment of the Pure Food and Drug Act and Meat Inspection Act. "The Treason of the Senate: Aldrich, the Head of it All", by David Graham Phillips, published as a series of articles in Cosmopolitan magazine in February 1906, described corruption in the U.S. Senate. This work was a keystone in the creation of the Seventeenth Amendment which established the election of Senators through popular vote.

It might be the second one