what does it mean by "to a suitable degree of accuracy?

[bitter patio]

you need to find the up and lb of a and then find to the greatest amount of sigfigs a number that both round to

so in this case ub and lb of a are 4.7579 and 4.69006 respectively

they both round to 5 as one sig fig

for 2 sig fig lb rounds to 4.7 but ub rounds to 4.8

so here suitable degree of accuracy will just have a as 5