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Finding the Fourth Proportional to 421.86, 631.76 and 247.98

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Solution

The fourth proportional to 421.86, 631.76 and 247.98 is: 371.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    421.86 : 631.76 = 247.98 : x
  2. Step 2: Convert to fraction form
    421.86/631.76 = 247.98/x
  3. Step 3: Cross multiply
    421.86x = 631.76 × 247.98
  4. Step 4: Simplify right side
    421.86x = 156,663.84
  5. Step 5: Solve for x
    x = 156,663.84/421.86
  6. Step 6: Final answer
    x = 371.36

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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.