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Finding the Fourth Proportional to 781.08, 1,077.85 and 486.35

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Solution

The fourth proportional to 781.08, 1,077.85 and 486.35 is: 671.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.08 : 1,077.85 = 486.35 : x
  2. Step 2: Convert to fraction form
    781.08/1,077.85 = 486.35/x
  3. Step 3: Cross multiply
    781.08x = 1,077.85 × 486.35
  4. Step 4: Simplify right side
    781.08x = 524,212.35
  5. Step 5: Solve for x
    x = 524,212.35/781.08
  6. Step 6: Final answer
    x = 671.14

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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.