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Finding the Fourth Proportional to 429.32, 643.90 and 155.54

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Solution

The fourth proportional to 429.32, 643.90 and 155.54 is: 233.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.32 : 643.90 = 155.54 : x
  2. Step 2: Convert to fraction form
    429.32/643.90 = 155.54/x
  3. Step 3: Cross multiply
    429.32x = 643.90 × 155.54
  4. Step 4: Simplify right side
    429.32x = 100,152.21
  5. Step 5: Solve for x
    x = 100,152.21/429.32
  6. Step 6: Final answer
    x = 233.28

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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.