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Finding the Fourth Proportional to 780.18, 1,169.61 and 369.09

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Solution

The fourth proportional to 780.18, 1,169.61 and 369.09 is: 553.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.18 : 1,169.61 = 369.09 : x
  2. Step 2: Convert to fraction form
    780.18/1,169.61 = 369.09/x
  3. Step 3: Cross multiply
    780.18x = 1,169.61 × 369.09
  4. Step 4: Simplify right side
    780.18x = 431,691.35
  5. Step 5: Solve for x
    x = 431,691.35/780.18
  6. Step 6: Final answer
    x = 553.32

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.