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Finding the Fourth Proportional to 1,272.80, 1,909.80 and 579.68

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Solution

The fourth proportional to 1,272.80, 1,909.80 and 579.68 is: 869.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,272.80 : 1,909.80 = 579.68 : x
  2. Step 2: Convert to fraction form
    1,272.80/1,909.80 = 579.68/x
  3. Step 3: Cross multiply
    1,272.80x = 1,909.80 × 579.68
  4. Step 4: Simplify right side
    1,272.80x = 1,107,063.32
  5. Step 5: Solve for x
    x = 1,107,063.32/1,272.80
  6. Step 6: Final answer
    x = 869.79

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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.