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Finding the Fourth Proportional to 782.20, 1,178.68 and 648.26

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Solution

The fourth proportional to 782.20, 1,178.68 and 648.26 is: 976.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    782.20 : 1,178.68 = 648.26 : x
  2. Step 2: Convert to fraction form
    782.20/1,178.68 = 648.26/x
  3. Step 3: Cross multiply
    782.20x = 1,178.68 × 648.26
  4. Step 4: Simplify right side
    782.20x = 764,091.10
  5. Step 5: Solve for x
    x = 764,091.10/782.20
  6. Step 6: Final answer
    x = 976.85

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.