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Finding the Fourth Proportional to 879.72, 1,319.74 and 392.76

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Solution

The fourth proportional to 879.72, 1,319.74 and 392.76 is: 589.21

Step by Step Solution

  1. Step 1: Write the proportion equation
    879.72 : 1,319.74 = 392.76 : x
  2. Step 2: Convert to fraction form
    879.72/1,319.74 = 392.76/x
  3. Step 3: Cross multiply
    879.72x = 1,319.74 × 392.76
  4. Step 4: Simplify right side
    879.72x = 518,341.08
  5. Step 5: Solve for x
    x = 518,341.08/879.72
  6. Step 6: Final answer
    x = 589.21

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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.