Ratio and Proportion: 0.5:20:: X: 200

The proportion equation of the ratio 100:2=60:X is

\(\frac{100}{2}=\frac{60}{X}\)

Cross-multiply to find the value of X

\(100x\ =\ 120\)

Divide both sides by 100

\(\frac{100x}{100}=\frac{120}{100}\)

\(x\ =\ 1.2\)

The value of X is 1.2

The ratio 0.5:20=X:200 to proportion equation becomes

\(\frac{0.5}{20}=\frac{X}{200}\)

Cross-multiply to find the value of X

\(0.5\ast200=20x\)

\(100=20x\)

Divide both sides by 20 to find the value of X

\(\frac{100}{20}=\frac{20x}{20}\)

\(5=x\)

Thus, the value of X is 5.

To change mL to L, use the relation 1000 mL = 1 L and apply dimension analysis as follows:

\(300\ mL\ast\frac{1L}{1000mL}=0.3\ L\)

Thus, 300 mL is equal to 0.3 L.

Compare the four fractions, find the least common divisor for denominators 7, 6, 9 and 8 which is 504.

Now multiply each fraction with 504 as:

\(\frac {3}{7} \ast 504 = 216\)

\(\frac {3}{6} \ast 504 = 252 \)

\(\frac {3}{9} \ast 504 = 168\)

\(\frac {3}{8} \ast 504 =189\)

From the above calculations, 252 is the greatest, which follows that 3/6 is the largest fraction.