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Finding the Fourth Proportional to 421.47, 631.70 and 190.47

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Solution

The fourth proportional to 421.47, 631.70 and 190.47 is: 285.47

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.47 : 631.70 = 190.47 : x
  2. Step 2: Convert to fraction form
    421.47/631.70 = 190.47/x
  3. Step 3: Cross multiply
    421.47x = 631.70 × 190.47
  4. Step 4: Simplify right side
    421.47x = 120,318.95
  5. Step 5: Solve for x
    x = 120,318.95/421.47
  6. Step 6: Final answer
    x = 285.47

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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.