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Finding the Fourth Proportional to 878.48, 1,212.28 and 485.48

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Solution

The fourth proportional to 878.48, 1,212.28 and 485.48 is: 669.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.48 : 1,212.28 = 485.48 : x
  2. Step 2: Convert to fraction form
    878.48/1,212.28 = 485.48/x
  3. Step 3: Cross multiply
    878.48x = 1,212.28 × 485.48
  4. Step 4: Simplify right side
    878.48x = 588,537.69
  5. Step 5: Solve for x
    x = 588,537.69/878.48
  6. Step 6: Final answer
    x = 669.95

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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.