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Finding the Fourth Proportional to 878.69, 1,209.01 and 805.79

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Solution

The fourth proportional to 878.69, 1,209.01 and 805.79 is: 1,108.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    878.69 : 1,209.01 = 805.79 : x
  2. Step 2: Convert to fraction form
    878.69/1,209.01 = 805.79/x
  3. Step 3: Cross multiply
    878.69x = 1,209.01 × 805.79
  4. Step 4: Simplify right side
    878.69x = 974,208.17
  5. Step 5: Solve for x
    x = 974,208.17/878.69
  6. Step 6: Final answer
    x = 1,108.71

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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.