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Finding the Fourth Proportional to 809.30, 1,212.15 and 654.86

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Solution

The fourth proportional to 809.30, 1,212.15 and 654.86 is: 980.83

Step by Step Solution

  1. Step 1: Write the proportion equation
    809.30 : 1,212.15 = 654.86 : x
  2. Step 2: Convert to fraction form
    809.30/1,212.15 = 654.86/x
  3. Step 3: Cross multiply
    809.30x = 1,212.15 × 654.86
  4. Step 4: Simplify right side
    809.30x = 793,788.55
  5. Step 5: Solve for x
    x = 793,788.55/809.30
  6. Step 6: Final answer
    x = 980.83

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.