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Finding the Fourth Proportional to 429.40, 643.75 and 155.32

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Solution

The fourth proportional to 429.40, 643.75 and 155.32 is: 232.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.40 : 643.75 = 155.32 : x
  2. Step 2: Convert to fraction form
    429.40/643.75 = 155.32/x
  3. Step 3: Cross multiply
    429.40x = 643.75 × 155.32
  4. Step 4: Simplify right side
    429.40x = 99,985.25
  5. Step 5: Solve for x
    x = 99,985.25/429.40
  6. Step 6: Final answer
    x = 232.85

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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.