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Finding the Fourth Proportional to 780.45, 1,076.81 and 518.01

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Solution

The fourth proportional to 780.45, 1,076.81 and 518.01 is: 714.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.45 : 1,076.81 = 518.01 : x
  2. Step 2: Convert to fraction form
    780.45/1,076.81 = 518.01/x
  3. Step 3: Cross multiply
    780.45x = 1,076.81 × 518.01
  4. Step 4: Simplify right side
    780.45x = 557,795.76
  5. Step 5: Solve for x
    x = 557,795.76/780.45
  6. Step 6: Final answer
    x = 714.71

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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.