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Finding the Fourth Proportional to 429.15, 643.90 and 185.50

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Solution

The fourth proportional to 429.15, 643.90 and 185.50 is: 278.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    429.15 : 643.90 = 185.50 : x
  2. Step 2: Convert to fraction form
    429.15/643.90 = 185.50/x
  3. Step 3: Cross multiply
    429.15x = 643.90 × 185.50
  4. Step 4: Simplify right side
    429.15x = 119,443.45
  5. Step 5: Solve for x
    x = 119,443.45/429.15
  6. Step 6: Final answer
    x = 278.33

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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.