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Finding the Fourth Proportional to 678.60, 936.90 and 612.18

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Solution

The fourth proportional to 678.60, 936.90 and 612.18 is: 845.20

Step by Step Solution

  1. Step 1: Write the proportion equation
    678.60 : 936.90 = 612.18 : x
  2. Step 2: Convert to fraction form
    678.60/936.90 = 612.18/x
  3. Step 3: Cross multiply
    678.60x = 936.90 × 612.18
  4. Step 4: Simplify right side
    678.60x = 573,551.44
  5. Step 5: Solve for x
    x = 573,551.44/678.60
  6. Step 6: Final answer
    x = 845.20

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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.