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Finding the Fourth Proportional to 431.46, 643.86 and 385.32

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Solution

The fourth proportional to 431.46, 643.86 and 385.32 is: 575.01

Step by Step Solution

  1. Step 1: Write the proportion equation
    431.46 : 643.86 = 385.32 : x
  2. Step 2: Convert to fraction form
    431.46/643.86 = 385.32/x
  3. Step 3: Cross multiply
    431.46x = 643.86 × 385.32
  4. Step 4: Simplify right side
    431.46x = 248,092.14
  5. Step 5: Solve for x
    x = 248,092.14/431.46
  6. Step 6: Final answer
    x = 575.01

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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.