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Finding the Fourth Proportional to 781.07, 1,077.87 and 431.75

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Solution

The fourth proportional to 781.07, 1,077.87 and 431.75 is: 595.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.07 : 1,077.87 = 431.75 : x
  2. Step 2: Convert to fraction form
    781.07/1,077.87 = 431.75/x
  3. Step 3: Cross multiply
    781.07x = 1,077.87 × 431.75
  4. Step 4: Simplify right side
    781.07x = 465,368.21
  5. Step 5: Solve for x
    x = 465,368.21/781.07
  6. Step 6: Final answer
    x = 595.81

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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.