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Finding the Fourth Proportional to 492.85, 738.90 and 421.21

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Solution

The fourth proportional to 492.85, 738.90 and 421.21 is: 631.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    492.85 : 738.90 = 421.21 : x
  2. Step 2: Convert to fraction form
    492.85/738.90 = 421.21/x
  3. Step 3: Cross multiply
    492.85x = 738.90 × 421.21
  4. Step 4: Simplify right side
    492.85x = 311,232.07
  5. Step 5: Solve for x
    x = 311,232.07/492.85
  6. Step 6: Final answer
    x = 631.49

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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.