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Finding the Fourth Proportional to 785.82, 1,178.28 and 419.70

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Solution

The fourth proportional to 785.82, 1,178.28 and 419.70 is: 629.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.82 : 1,178.28 = 419.70 : x
  2. Step 2: Convert to fraction form
    785.82/1,178.28 = 419.70/x
  3. Step 3: Cross multiply
    785.82x = 1,178.28 × 419.70
  4. Step 4: Simplify right side
    785.82x = 494,524.12
  5. Step 5: Solve for x
    x = 494,524.12/785.82
  6. Step 6: Final answer
    x = 629.31

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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.