Answer
a) 42.4 is incorrect and should be rounded down to 42.3
b) 57.0 is correct
c) 232 is correct
d) 0.046 is incorrect and the answer should be 0.0456
Work Step by Step
a) 42.3492 should be rounded down to 42.3 instead of 42.4 because after the third digit the value of the digit is 4 which is less than 5 and thus the digit prior should be rounded down to 3.
b) 56.9971 correctly rounds up to 57 as the 4th digit is 9 which rounds up and since the digit before is also a 9, the next nearest whole number is correct with one decimal place.
c) 231.904 correctly rounds up to 232 as the 4th digit is 9 which rounds up and since the digit before is also a 9, the next nearest whole number is correct with no decimal places.
d) 0.04555 rounds up to 0.0456 because the 4th significant figure is 5 and so it should be rounded up to 0.0456 to 3 significant figures.