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Finding the Fourth Proportional to 856.86, 1,279.56 and 672.18

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Solution

The fourth proportional to 856.86, 1,279.56 and 672.18 is: 1,003.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    856.86 : 1,279.56 = 672.18 : x
  2. Step 2: Convert to fraction form
    856.86/1,279.56 = 672.18/x
  3. Step 3: Cross multiply
    856.86x = 1,279.56 × 672.18
  4. Step 4: Simplify right side
    856.86x = 860,094.64
  5. Step 5: Solve for x
    x = 860,094.64/856.86
  6. Step 6: Final answer
    x = 1,003.77

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.