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Finding the Fourth Proportional to 256.77, 384.89 and 128.25

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Solution

The fourth proportional to 256.77, 384.89 and 128.25 is: 192.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.77 : 384.89 = 128.25 : x
  2. Step 2: Convert to fraction form
    256.77/384.89 = 128.25/x
  3. Step 3: Cross multiply
    256.77x = 384.89 × 128.25
  4. Step 4: Simplify right side
    256.77x = 49,361.50
  5. Step 5: Solve for x
    x = 49,361.50/256.77
  6. Step 6: Final answer
    x = 192.24

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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.