Attempting to Measure the Ideal Gas Constant (16/20)
This is the only part of the process that's spreadsheet program specific. You want to make a scatter plot that doesn't connect the dots. The whole point of doing this is to get a graph and to fit a best fit line to that graph, so any dot connecting gets in the way.
See Dowd if you need help with your preferred spreadsheet. (Unless it's Excel in Office 365, in which case you're out of luck.)
Attempting to Measure the Ideal Gas Constant (16/20)
This is the only part of the process that's spreadsheet program specific. You want to make a scatter plot that doesn't connect the dots. The whole point of doing this is to get a graph and to fit a best fit line to that graph, so any dot connecting gets in the way.
See Dowd if you need help with your preferred spreadsheet. (Unless it's Excel in Office 365, in which case you're out of luck.)