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Finding the Fourth Proportional to 256.60, 384.90 and 231.40

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Solution

The fourth proportional to 256.60, 384.90 and 231.40 is: 347.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.60 : 384.90 = 231.40 : x
  2. Step 2: Convert to fraction form
    256.60/384.90 = 231.40/x
  3. Step 3: Cross multiply
    256.60x = 384.90 × 231.40
  4. Step 4: Simplify right side
    256.60x = 89,065.86
  5. Step 5: Solve for x
    x = 89,065.86/256.60
  6. Step 6: Final answer
    x = 347.10

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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.