Home / 1,286.48-1,929.90-420.77

Finding the Fourth Proportional to 1,286.48, 1,929.90 and 420.77

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Solution

The fourth proportional to 1,286.48, 1,929.90 and 420.77 is: 631.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,286.48 : 1,929.90 = 420.77 : x
  2. Step 2: Convert to fraction form
    1,286.48/1,929.90 = 420.77/x
  3. Step 3: Cross multiply
    1,286.48x = 1,929.90 × 420.77
  4. Step 4: Simplify right side
    1,286.48x = 812,044.02
  5. Step 5: Solve for x
    x = 812,044.02/1,286.48
  6. Step 6: Final answer
    x = 631.21

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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.