Question

Given: 1 pound (lb) = 453.6 grams 1 pound = 16 ounces (oz) how many ounces are equal to 0.0003140 kilograms? taking significant figures into account, the correctly expressed answer is 1. 1 × 10−2 oz 2. 1.1 × 10−2 oz 3. 1.108 × 10−2 oz 4. 1.11 × 10−2 oz 5. 1.1076 × 10−2 oz

Answer 1

we have that

1 pound (lb) = 453.6 grams

1 pound (lb) = 16 ounces (oz)

so

453.6 grams = 16 ounces (oz)

453.6 grams-------> convert to Kg-----> 453.6/100=0.4536 Kg

0.4536 Kg = 16 ounces (oz)

we know that

Zeroes at the end of numbers containing a decimal  point are considered to be significant,

so

the number 0.0003140 kg ------> has 4 significant figures

by proportion

$\frac{16}{0.4536} \frac{oz}{kg} = \frac{x}{0.0003140} \frac{oz}{kg} \\ \\0.0003140*16=0.4536*x \\\\ x= \frac{0.0003140*16}{0.4536} \\\\ x= 0.01108\ ounces$

$x= 0.01108= 1.108*10^{-2} \ oz$ ----> this number has 4 significant figures

therefore

the answer is

$1.108*10^{-2} \ oz$