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Finding the Fourth Proportional to 621.20, 857.88 and 511.76

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Solution

The fourth proportional to 621.20, 857.88 and 511.76 is: 706.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.20 : 857.88 = 511.76 : x
  2. Step 2: Convert to fraction form
    621.20/857.88 = 511.76/x
  3. Step 3: Cross multiply
    621.20x = 857.88 × 511.76
  4. Step 4: Simplify right side
    621.20x = 439,028.67
  5. Step 5: Solve for x
    x = 439,028.67/621.20
  6. Step 6: Final answer
    x = 706.74

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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.