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Finding the Fourth Proportional to 879.28, 1,318.80 and 392.21

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Solution

The fourth proportional to 879.28, 1,318.80 and 392.21 is: 588.26

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.28 : 1,318.80 = 392.21 : x
  2. Step 2: Convert to fraction form
    879.28/1,318.80 = 392.21/x
  3. Step 3: Cross multiply
    879.28x = 1,318.80 × 392.21
  4. Step 4: Simplify right side
    879.28x = 517,244.59
  5. Step 5: Solve for x
    x = 517,244.59/879.28
  6. Step 6: Final answer
    x = 588.26

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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.