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Finding the Fourth Proportional to 879.30, 1,319.55 and 392.61

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Solution

The fourth proportional to 879.30, 1,319.55 and 392.61 is: 589.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.30 : 1,319.55 = 392.61 : x
  2. Step 2: Convert to fraction form
    879.30/1,319.55 = 392.61/x
  3. Step 3: Cross multiply
    879.30x = 1,319.55 × 392.61
  4. Step 4: Simplify right side
    879.30x = 518,068.53
  5. Step 5: Solve for x
    x = 518,068.53/879.30
  6. Step 6: Final answer
    x = 589.18

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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.