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Finding the Fourth Proportional to 879.90, 1,319.37 and 392.70

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Solution

The fourth proportional to 879.90, 1,319.37 and 392.70 is: 588.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.90 : 1,319.37 = 392.70 : x
  2. Step 2: Convert to fraction form
    879.90/1,319.37 = 392.70/x
  3. Step 3: Cross multiply
    879.90x = 1,319.37 × 392.70
  4. Step 4: Simplify right side
    879.90x = 518,116.60
  5. Step 5: Solve for x
    x = 518,116.60/879.90
  6. Step 6: Final answer
    x = 588.84

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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.