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Finding the Fourth Proportional to 256.78, 354.39 and 151.91

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Solution

The fourth proportional to 256.78, 354.39 and 151.91 is: 209.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    256.78 : 354.39 = 151.91 : x
  2. Step 2: Convert to fraction form
    256.78/354.39 = 151.91/x
  3. Step 3: Cross multiply
    256.78x = 354.39 × 151.91
  4. Step 4: Simplify right side
    256.78x = 53,833.23
  5. Step 5: Solve for x
    x = 53,833.23/256.78
  6. Step 6: Final answer
    x = 209.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.