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Finding the Fourth Proportional to 331.40, 457.12 and 287.64

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Solution

The fourth proportional to 331.40, 457.12 and 287.64 is: 396.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    331.40 : 457.12 = 287.64 : x
  2. Step 2: Convert to fraction form
    331.40/457.12 = 287.64/x
  3. Step 3: Cross multiply
    331.40x = 457.12 × 287.64
  4. Step 4: Simplify right side
    331.40x = 131,486.00
  5. Step 5: Solve for x
    x = 131,486.00/331.40
  6. Step 6: Final answer
    x = 396.76

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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.