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Finding the Fourth Proportional to 645.96, 891.19 and 409.85

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Solution

The fourth proportional to 645.96, 891.19 and 409.85 is: 565.44

Step by Step Solution

  1. Step 1: Write the proportion equation
    645.96 : 891.19 = 409.85 : x
  2. Step 2: Convert to fraction form
    645.96/891.19 = 409.85/x
  3. Step 3: Cross multiply
    645.96x = 891.19 × 409.85
  4. Step 4: Simplify right side
    645.96x = 365,254.22
  5. Step 5: Solve for x
    x = 365,254.22/645.96
  6. Step 6: Final answer
    x = 565.44

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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.