Home / 1,242.18-1,861.56-721.85

Finding the Fourth Proportional to 1,242.18, 1,861.56 and 721.85

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Solution

The fourth proportional to 1,242.18, 1,861.56 and 721.85 is: 1,081.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,242.18 : 1,861.56 = 721.85 : x
  2. Step 2: Convert to fraction form
    1,242.18/1,861.56 = 721.85/x
  3. Step 3: Cross multiply
    1,242.18x = 1,861.56 × 721.85
  4. Step 4: Simplify right side
    1,242.18x = 1,343,757.78
  5. Step 5: Solve for x
    x = 1,343,757.78/1,242.18
  6. Step 6: Final answer
    x = 1,081.77

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.