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Finding the Fourth Proportional to 492.10, 678.26 and 398.50

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Solution

The fourth proportional to 492.10, 678.26 and 398.50 is: 549.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    492.10 : 678.26 = 398.50 : x
  2. Step 2: Convert to fraction form
    492.10/678.26 = 398.50/x
  3. Step 3: Cross multiply
    492.10x = 678.26 × 398.50
  4. Step 4: Simplify right side
    492.10x = 270,286.61
  5. Step 5: Solve for x
    x = 270,286.61/492.10
  6. Step 6: Final answer
    x = 549.25

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.