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Finding the Fourth Proportional to 381.02, 525.50 and 287.78

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Solution

The fourth proportional to 381.02, 525.50 and 287.78 is: 396.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    381.02 : 525.50 = 287.78 : x
  2. Step 2: Convert to fraction form
    381.02/525.50 = 287.78/x
  3. Step 3: Cross multiply
    381.02x = 525.50 × 287.78
  4. Step 4: Simplify right side
    381.02x = 151,228.39
  5. Step 5: Solve for x
    x = 151,228.39/381.02
  6. Step 6: Final answer
    x = 396.90

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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.