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Finding the Fourth Proportional to 780.78, 1,077.53 and 449.30

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Solution

The fourth proportional to 780.78, 1,077.53 and 449.30 is: 620.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.78 : 1,077.53 = 449.30 : x
  2. Step 2: Convert to fraction form
    780.78/1,077.53 = 449.30/x
  3. Step 3: Cross multiply
    780.78x = 1,077.53 × 449.30
  4. Step 4: Simplify right side
    780.78x = 484,134.23
  5. Step 5: Solve for x
    x = 484,134.23/780.78
  6. Step 6: Final answer
    x = 620.06

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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.