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Finding the Fourth Proportional to 780.87, 1,171.32 and 342.03

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Solution

The fourth proportional to 780.87, 1,171.32 and 342.03 is: 513.06

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.87 : 1,171.32 = 342.03 : x
  2. Step 2: Convert to fraction form
    780.87/1,171.32 = 342.03/x
  3. Step 3: Cross multiply
    780.87x = 1,171.32 × 342.03
  4. Step 4: Simplify right side
    780.87x = 400,631.61
  5. Step 5: Solve for x
    x = 400,631.61/780.87
  6. Step 6: Final answer
    x = 513.06

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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.