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Finding the Fourth Proportional to 428.46, 643.30 and 185.46

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Solution

The fourth proportional to 428.46, 643.30 and 185.46 is: 278.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    428.46 : 643.30 = 185.46 : x
  2. Step 2: Convert to fraction form
    428.46/643.30 = 185.46/x
  3. Step 3: Cross multiply
    428.46x = 643.30 × 185.46
  4. Step 4: Simplify right side
    428.46x = 119,306.42
  5. Step 5: Solve for x
    x = 119,306.42/428.46
  6. Step 6: Final answer
    x = 278.45

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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.