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Finding the Fourth Proportional to 667.68, 1,000.78 and 256.64

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Solution

The fourth proportional to 667.68, 1,000.78 and 256.64 is: 384.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    667.68 : 1,000.78 = 256.64 : x
  2. Step 2: Convert to fraction form
    667.68/1,000.78 = 256.64/x
  3. Step 3: Cross multiply
    667.68x = 1,000.78 × 256.64
  4. Step 4: Simplify right side
    667.68x = 256,840.18
  5. Step 5: Solve for x
    x = 256,840.18/667.68
  6. Step 6: Final answer
    x = 384.68

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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.