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Finding the Fourth Proportional to 492.12, 678.84 and 305.58

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Solution

The fourth proportional to 492.12, 678.84 and 305.58 is: 421.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    492.12 : 678.84 = 305.58 : x
  2. Step 2: Convert to fraction form
    492.12/678.84 = 305.58/x
  3. Step 3: Cross multiply
    492.12x = 678.84 × 305.58
  4. Step 4: Simplify right side
    492.12x = 207,439.93
  5. Step 5: Solve for x
    x = 207,439.93/492.12
  6. Step 6: Final answer
    x = 421.52

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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.