The phrase "a solid indication of" is correct and usable in written English.
It can be used when you want to express that something provides strong evidence or a clear sign of a particular situation or outcome.
Example: "The increase in sales figures is a solid indication of the effectiveness of our new marketing strategy."
Alternatives: "a strong sign of" or "a clear indication of".
"It's really a solid indication of the future of input technology," she wrote.
This sentence below clearly gives us a solid indication of what drives your passion to learn and continue to contribute in such a significant manner.
The result blends qualitative and benchmarked data on other C-suite executives to give us a solid indication of each individual's abilities, mindset, and development needs.
That maiden sale was a solid indication of China's interest in promoting its currency in global trade and investment via yuan-denominated bonds: CDB is one of three banks in China responsible for raising funds for infrastructure projects such as the Three Gorges Dam and Shanghai Pudong International Airport.
The category of total appeal is a solid indication of how attractive a candidate is as a presidential contender.
The Pure IPO should also give us a solid indication of the market mood: are people hungry for a piece of storage startups?
After an initial round of puzzlement over this selection, conservatives backed the nomination, even though Roberts never gave any solid indication of whether he agreed with the philosophy of judicial restraint.
When the press release said it would be available in 57 countries I believe this gave a solid indication that the supply of them would be better than what others were expecting.
A more solid indication of Stevens's commitment to practice what it preaches is its redoubled efforts to launch institute-generated technology companies, even at the expense of current programs.
The report gives a very solid indication of just how much the crowdfunding industry has changed over the last few years (and will continue to change).
Producers of the show were expecting close to $1 million in ticket sales by day's end, a solid indication that an Italian-language opera can succeed on Broadway.
