Home / 742.03-1,021.62-643.21

Finding the Fourth Proportional to 742.03, 1,021.62 and 643.21

Calculator

Solution

The fourth proportional to 742.03, 1,021.62 and 643.21 is: 885.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    742.03 : 1,021.62 = 643.21 : x
  2. Step 2: Convert to fraction form
    742.03/1,021.62 = 643.21/x
  3. Step 3: Cross multiply
    742.03x = 1,021.62 × 643.21
  4. Step 4: Simplify right side
    742.03x = 657,116.20
  5. Step 5: Solve for x
    x = 657,116.20/742.03
  6. Step 6: Final answer
    x = 885.57

Related Problems

Find fourth proportional to 371.02, 510.81 and 321.61
Half scale
Find fourth proportional to 1,484.06, 2,043.24 and 1,286.42
Double scale
Find fourth proportional to 743.03, 1,023 and 644.21
Similar ratio
Find fourth proportional to 1,113.05, 1,532.43 and 964.82
1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.