For the fist part you simply substitute 10 in for x to the equation to get the corresponding y value
y = 11(10) + 340
y = 110 + 340
y = 450
For the second part of that question, do you think this matches a point on the scatterplot.....more than likely this is a NO, as generally speaking a line of best fit doesn't pass through many of the data points that it uses to create the equation for the line, so I'd say probably not.
Hope this helps.
Brian
