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Finding the Fourth Proportional to 878.05, 1,211.69 and 485.07

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Solution

The fourth proportional to 878.05, 1,211.69 and 485.07 is: 669.39

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.05 : 1,211.69 = 485.07 : x
  2. Step 2: Convert to fraction form
    878.05/1,211.69 = 485.07/x
  3. Step 3: Cross multiply
    878.05x = 1,211.69 × 485.07
  4. Step 4: Simplify right side
    878.05x = 587,752.04
  5. Step 5: Solve for x
    x = 587,752.04/878.05
  6. Step 6: Final answer
    x = 669.39

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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.