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Finding the Fourth Proportional to 428.97, 643.72 and 155.04

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Solution

The fourth proportional to 428.97, 643.72 and 155.04 is: 232.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.97 : 643.72 = 155.04 : x
  2. Step 2: Convert to fraction form
    428.97/643.72 = 155.04/x
  3. Step 3: Cross multiply
    428.97x = 643.72 × 155.04
  4. Step 4: Simplify right side
    428.97x = 99,802.35
  5. Step 5: Solve for x
    x = 99,802.35/428.97
  6. Step 6: Final answer
    x = 232.66

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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.