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Finding the Fourth Proportional to 788.89, 1,181.17 and 642.30

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Solution

The fourth proportional to 788.89, 1,181.17 and 642.30 is: 961.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    788.89 : 1,181.17 = 642.30 : x
  2. Step 2: Convert to fraction form
    788.89/1,181.17 = 642.30/x
  3. Step 3: Cross multiply
    788.89x = 1,181.17 × 642.30
  4. Step 4: Simplify right side
    788.89x = 758,664.14
  5. Step 5: Solve for x
    x = 758,664.14/788.89
  6. Step 6: Final answer
    x = 961.68

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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.