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Finding the Fourth Proportional to 781.82, 1,079.67 and 487.22

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Solution

The fourth proportional to 781.82, 1,079.67 and 487.22 is: 672.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.82 : 1,079.67 = 487.22 : x
  2. Step 2: Convert to fraction form
    781.82/1,079.67 = 487.22/x
  3. Step 3: Cross multiply
    781.82x = 1,079.67 × 487.22
  4. Step 4: Simplify right side
    781.82x = 526,036.82
  5. Step 5: Solve for x
    x = 526,036.82/781.82
  6. Step 6: Final answer
    x = 672.84

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.