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Finding the Fourth Proportional to 780.73, 1,170.81 and 415.31

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Solution

The fourth proportional to 780.73, 1,170.81 and 415.31 is: 622.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.73 : 1,170.81 = 415.31 : x
  2. Step 2: Convert to fraction form
    780.73/1,170.81 = 415.31/x
  3. Step 3: Cross multiply
    780.73x = 1,170.81 × 415.31
  4. Step 4: Simplify right side
    780.73x = 486,243.25
  5. Step 5: Solve for x
    x = 486,243.25/780.73
  6. Step 6: Final answer
    x = 622.81

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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.