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Finding the Fourth Proportional to 621.12, 931.68 and 511.80

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Solution

The fourth proportional to 621.12, 931.68 and 511.80 is: 767.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.12 : 931.68 = 511.80 : x
  2. Step 2: Convert to fraction form
    621.12/931.68 = 511.80/x
  3. Step 3: Cross multiply
    621.12x = 931.68 × 511.80
  4. Step 4: Simplify right side
    621.12x = 476,833.82
  5. Step 5: Solve for x
    x = 476,833.82/621.12
  6. Step 6: Final answer
    x = 767.70

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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.