Final answer:
To express 71/1000 as a decimal, divide the numerator by the denominator. To round 3.864 to the nearest tenth, look at the digit in the hundredth place. Forty nine thousandths can be expressed as the decimal number 0.049.
Step-by-step explanation:
To express a fraction as a decimal, divide the numerator by the denominator. Therefore, 71/1000 can be expressed as 0.071.
To round a number to the nearest tenth, look at the digit in the hundredth place. If it is 5 or above, round up; if it is 4 or below, round down. Therefore, 3.864 rounded to the nearest tenth is 3.9.
Forty nine thousandths can be expressed as the decimal number 0.049.
Learn more about Converting fractions to decimals