Question

If a= 4.2 to (1dp) and b = 18 (to the nearest whole number), Find the lower and upper bound of the following: ((a+b)/a)

Answer 1

Lower bound = 5.2

Upper bound = 5.4

Explanation:

If a= 4.2 to (1dp):

Upper bound = 4.2 + 0.05 = 4.25

Lower bound = 4.2 - 0.05 = 4.15

If b = 18 (to the nearest whole number)

Upper bound = 18 + 0.5 = 18.5

Lower bound = 18 - 0.5 = 17.5

Therefore:

Lower bound of ((a+b)/a) = ((4.15 + 17.5) / 4.15) = 5.2 to 1 decimal place

Upper bound of ((a+b)/a) = ((4.25 + 18.5) / 4.25) = 5.4 to 1 decimal place

The upper and lower bound are calculated to one decimal place.