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Finding the Fourth Proportional to 1,209.08, 1,812.26 and 721.11

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Solution

The fourth proportional to 1,209.08, 1,812.26 and 721.11 is: 1,080.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,209.08 : 1,812.26 = 721.11 : x
  2. Step 2: Convert to fraction form
    1,209.08/1,812.26 = 721.11/x
  3. Step 3: Cross multiply
    1,209.08x = 1,812.26 × 721.11
  4. Step 4: Simplify right side
    1,209.08x = 1,306,838.81
  5. Step 5: Solve for x
    x = 1,306,838.81/1,209.08
  6. Step 6: Final answer
    x = 1,080.85

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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.