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Finding the Fourth Proportional to 431.52, 643.97 and 385.39

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Solution

The fourth proportional to 431.52, 643.97 and 385.39 is: 575.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.52 : 643.97 = 385.39 : x
  2. Step 2: Convert to fraction form
    431.52/643.97 = 385.39/x
  3. Step 3: Cross multiply
    431.52x = 643.97 × 385.39
  4. Step 4: Simplify right side
    431.52x = 248,176.06
  5. Step 5: Solve for x
    x = 248,176.06/431.52
  6. Step 6: Final answer
    x = 575.12

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.