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Finding the Fourth Proportional to 436.78, 655.17 and 128.71

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Solution

The fourth proportional to 436.78, 655.17 and 128.71 is: 193.07

Step by Step Solution

  1. Step 1: Write the proportion equation
    436.78 : 655.17 = 128.71 : x
  2. Step 2: Convert to fraction form
    436.78/655.17 = 128.71/x
  3. Step 3: Cross multiply
    436.78x = 655.17 × 128.71
  4. Step 4: Simplify right side
    436.78x = 84,326.93
  5. Step 5: Solve for x
    x = 84,326.93/436.78
  6. Step 6: Final answer
    x = 193.07

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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.