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Finding the Fourth Proportional to 1,269, 1,903.50 and 720.72

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Solution

The fourth proportional to 1,269, 1,903.50 and 720.72 is: 1,081.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,269 : 1,903.50 = 720.72 : x
  2. Step 2: Convert to fraction form
    1,269/1,903.50 = 720.72/x
  3. Step 3: Cross multiply
    1,269x = 1,903.50 × 720.72
  4. Step 4: Simplify right side
    1,269x = 1,371,890.52
  5. Step 5: Solve for x
    x = 1,371,890.52/1,269
  6. Step 6: Final answer
    x = 1,081.08

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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.