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Finding the Fourth Proportional to 879, 1,318.65 and 385.38

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Solution

The fourth proportional to 879, 1,318.65 and 385.38 is: 578.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    879 : 1,318.65 = 385.38 : x
  2. Step 2: Convert to fraction form
    879/1,318.65 = 385.38/x
  3. Step 3: Cross multiply
    879x = 1,318.65 × 385.38
  4. Step 4: Simplify right side
    879x = 508,181.34
  5. Step 5: Solve for x
    x = 508,181.34/879
  6. Step 6: Final answer
    x = 578.14

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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.