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Finding the Fourth Proportional to 780.36, 1,076.78 and 481.90

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Solution

The fourth proportional to 780.36, 1,076.78 and 481.90 is: 664.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.36 : 1,076.78 = 481.90 : x
  2. Step 2: Convert to fraction form
    780.36/1,076.78 = 481.90/x
  3. Step 3: Cross multiply
    780.36x = 1,076.78 × 481.90
  4. Step 4: Simplify right side
    780.36x = 518,900.28
  5. Step 5: Solve for x
    x = 518,900.28/780.36
  6. Step 6: Final answer
    x = 664.95

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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.