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Finding the Fourth Proportional to 665.41, 997.20 and 421.50

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Solution

The fourth proportional to 665.41, 997.20 and 421.50 is: 631.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    665.41 : 997.20 = 421.50 : x
  2. Step 2: Convert to fraction form
    665.41/997.20 = 421.50/x
  3. Step 3: Cross multiply
    665.41x = 997.20 × 421.50
  4. Step 4: Simplify right side
    665.41x = 420,319.80
  5. Step 5: Solve for x
    x = 420,319.80/665.41
  6. Step 6: Final answer
    x = 631.67

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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.