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Finding the Fourth Proportional to 256.54, 384.33 and 128.38

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Solution

The fourth proportional to 256.54, 384.33 and 128.38 is: 192.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.54 : 384.33 = 128.38 : x
  2. Step 2: Convert to fraction form
    256.54/384.33 = 128.38/x
  3. Step 3: Cross multiply
    256.54x = 384.33 × 128.38
  4. Step 4: Simplify right side
    256.54x = 49,340.29
  5. Step 5: Solve for x
    x = 49,340.29/256.54
  6. Step 6: Final answer
    x = 192.33

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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.