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Finding the Fourth Proportional to 428.60, 643.10 and 185.19

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Solution

The fourth proportional to 428.60, 643.10 and 185.19 is: 277.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.60 : 643.10 = 185.19 : x
  2. Step 2: Convert to fraction form
    428.60/643.10 = 185.19/x
  3. Step 3: Cross multiply
    428.60x = 643.10 × 185.19
  4. Step 4: Simplify right side
    428.60x = 119,094.76
  5. Step 5: Solve for x
    x = 119,094.76/428.60
  6. Step 6: Final answer
    x = 277.87

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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.