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Finding the Fourth Proportional to 780.88, 1,169.84 and 396.40

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Solution

The fourth proportional to 780.88, 1,169.84 and 396.40 is: 593.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.88 : 1,169.84 = 396.40 : x
  2. Step 2: Convert to fraction form
    780.88/1,169.84 = 396.40/x
  3. Step 3: Cross multiply
    780.88x = 1,169.84 × 396.40
  4. Step 4: Simplify right side
    780.88x = 463,724.58
  5. Step 5: Solve for x
    x = 463,724.58/780.88
  6. Step 6: Final answer
    x = 593.85

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.