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Finding the Fourth Proportional to 428.77, 643.46 and 185.37

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Solution

The fourth proportional to 428.77, 643.46 and 185.37 is: 278.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.77 : 643.46 = 185.37 : x
  2. Step 2: Convert to fraction form
    428.77/643.46 = 185.37/x
  3. Step 3: Cross multiply
    428.77x = 643.46 × 185.37
  4. Step 4: Simplify right side
    428.77x = 119,278.18
  5. Step 5: Solve for x
    x = 119,278.18/428.77
  6. Step 6: Final answer
    x = 278.19

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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.