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Finding the Fourth Proportional to 723.72, 1,085.68 and 285

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Solution

The fourth proportional to 723.72, 1,085.68 and 285 is: 427.54

Step by Step Solution

  1. Step 1: Write the proportion equation
    723.72 : 1,085.68 = 285 : x
  2. Step 2: Convert to fraction form
    723.72/1,085.68 = 285/x
  3. Step 3: Cross multiply
    723.72x = 1,085.68 × 285
  4. Step 4: Simplify right side
    723.72x = 309,418.80
  5. Step 5: Solve for x
    x = 309,418.80/723.72
  6. Step 6: Final answer
    x = 427.54

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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.