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Finding the Fourth Proportional to 780.70, 1,077.36 and 449.12

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Solution

The fourth proportional to 780.70, 1,077.36 and 449.12 is: 619.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.70 : 1,077.36 = 449.12 : x
  2. Step 2: Convert to fraction form
    780.70/1,077.36 = 449.12/x
  3. Step 3: Cross multiply
    780.70x = 1,077.36 × 449.12
  4. Step 4: Simplify right side
    780.70x = 483,863.92
  5. Step 5: Solve for x
    x = 483,863.92/780.70
  6. Step 6: Final answer
    x = 619.78

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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.