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Finding the Fourth Proportional to 621.21, 856.99 and 385.10

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Solution

The fourth proportional to 621.21, 856.99 and 385.10 is: 531.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.21 : 856.99 = 385.10 : x
  2. Step 2: Convert to fraction form
    621.21/856.99 = 385.10/x
  3. Step 3: Cross multiply
    621.21x = 856.99 × 385.10
  4. Step 4: Simplify right side
    621.21x = 330,026.98
  5. Step 5: Solve for x
    x = 330,026.98/621.21
  6. Step 6: Final answer
    x = 531.26

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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.