The phrase "and checked how" is correct and usable in written English.
It can be used when describing an action of verifying or examining a method or process.
Example: "I conducted the experiment and checked how the variables affected the outcome."
Alternatives: "and verified how" or "and assessed how".
I looked at an encyclopaedia of literature and checked how old people were when they wrote their famous works.
We then compared the ratio of native to exotic species and checked how many native species of the fragment were also in the surrounding treescape.
We changed electromagnetic pumping frequency and checked how different frequencies change the local density of states in the tubulin protein structure.
Using a sugar-specialized structure modeling program developed by Agirre, they analyzed the raw x-ray data of each sugar deposited in the database to determine its expected shape and checked how well it matched the structure reported.
Kathay Feng, executive director of California Common Cause, said that politicians should have been cautious and checked how much the tickets were worth, especially given the frenzy around the show.
Otherwise they never came and checked how things were or asked if the breastfeeding was going OK.
I went online this morning to tap in my postcode and check how much crime takes place in my street.
Make sure you understand all these fees and check how much they are before you sign up.
Ask the Swiss about their negotiations with the EU about bank secrecy and withholding taxes on savings accounts, and check how enjoyable those were.
Cry? Lunge for the nearest laptop and check how your weight compares, graphically-speaking, to its value this time last year, last month, yesterday?
"Doctors tell patients to take an aspirin a day, but we don't go back and check how much it thins their blood".
