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Finding the Fourth Proportional to 256.68, 384.90 and 83.30

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Solution

The fourth proportional to 256.68, 384.90 and 83.30 is: 124.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.68 : 384.90 = 83.30 : x
  2. Step 2: Convert to fraction form
    256.68/384.90 = 83.30/x
  3. Step 3: Cross multiply
    256.68x = 384.90 × 83.30
  4. Step 4: Simplify right side
    256.68x = 32,060.25
  5. Step 5: Solve for x
    x = 32,060.25/256.68
  6. Step 6: Final answer
    x = 124.90

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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.