data too
data correlating masks with covid cases, hospitalizations or deaths?
example:
https://rationalground.com/interactive-tool-masks-covid-19/
'The survey was conducted in the middle of July and v to July 15th through Sept 15th.
The line shows a positive or negative correlation. If masks do indeed work you would expect to see a line sloping downward. Hover over the line to get your R-square and P values.'