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Finding the Fourth Proportional to 621.18, 856.45 and 521.98

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Solution

The fourth proportional to 621.18, 856.45 and 521.98 is: 719.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.18 : 856.45 = 521.98 : x
  2. Step 2: Convert to fraction form
    621.18/856.45 = 521.98/x
  3. Step 3: Cross multiply
    621.18x = 856.45 × 521.98
  4. Step 4: Simplify right side
    621.18x = 447,049.77
  5. Step 5: Solve for x
    x = 447,049.77/621.18
  6. Step 6: Final answer
    x = 719.68

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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.