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Finding the Fourth Proportional to 780.55, 1,076.11 and 647.27

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Solution

The fourth proportional to 780.55, 1,076.11 and 647.27 is: 892.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.55 : 1,076.11 = 647.27 : x
  2. Step 2: Convert to fraction form
    780.55/1,076.11 = 647.27/x
  3. Step 3: Cross multiply
    780.55x = 1,076.11 × 647.27
  4. Step 4: Simplify right side
    780.55x = 696,533.72
  5. Step 5: Solve for x
    x = 696,533.72/780.55
  6. Step 6: Final answer
    x = 892.36

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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.