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Finding the Fourth Proportional to 620.85, 856.17 and 411.21

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Solution

The fourth proportional to 620.85, 856.17 and 411.21 is: 567.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    620.85 : 856.17 = 411.21 : x
  2. Step 2: Convert to fraction form
    620.85/856.17 = 411.21/x
  3. Step 3: Cross multiply
    620.85x = 856.17 × 411.21
  4. Step 4: Simplify right side
    620.85x = 352,065.67
  5. Step 5: Solve for x
    x = 352,065.67/620.85
  6. Step 6: Final answer
    x = 567.07

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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.