It will take 26.1 minutes because 5.22x5 is equal to 26.1
Are you saying that $1050 was the initial amount of money in the savings account? If so then you'd find 84% of 1050, which is 1050*.84. (.84 is the decimal version of 84%)
Just plug in the x-values into the given equation to find. For 9-19-19 whatever the number is correlated to how much the graph is being moved down or up and the x is your slope.