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Finding the Fourth Proportional to 809.85, 1,117.57 and 478.31

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Solution

The fourth proportional to 809.85, 1,117.57 and 478.31 is: 660.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.85 : 1,117.57 = 478.31 : x
  2. Step 2: Convert to fraction form
    809.85/1,117.57 = 478.31/x
  3. Step 3: Cross multiply
    809.85x = 1,117.57 × 478.31
  4. Step 4: Simplify right side
    809.85x = 534,540.37
  5. Step 5: Solve for x
    x = 534,540.37/809.85
  6. Step 6: Final answer
    x = 660.05

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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.