LONDON — When Rishi Sunak was elected to Parliament in 2015, he recalled a piece of advice from his father-in-law, Narayana Murthy, a technology billionaire who is one of India’s richest men. “In God we trust,” Mr. Murthy told him, “but everyone else needs to bring data to the table.”

Now 39 years old and Britain’s top finance official, Mr. Sunak is trying to apply that lesson to the greatest economic rescue in the post-World War II history of the country. As chancellor of the Exchequer, Mr. Sunak has orchestrated a series of increasingly desperate efforts to protect Britain’s 66 million people from the sudden dislocation brought on by the coronavirus pandemic.

On Thursday, Mr. Sunak rolled out the latest — a package to pay 80 percent of the earnings of self-employed people who lost income because of the lockdown of the country. That came on top of measures last week to compensate people laid off from companies and more than $300 billion in aid for distressed businesses.

In the process, Mr. Sunak, who was thrust into his job six weeks ago, has become one of the stars of this crisis. On one level, that is not surprising: his job, after all, is to dole out money. But beyond that, commentators say, Mr. Sunak’s grave, self-assured delivery and empathetic tone are proving a better match for the moment than the shambling levity of Prime Minister Boris Johnson.