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Finding the Fourth Proportional to 780.15, 1,169.20 and 697.39

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Solution

The fourth proportional to 780.15, 1,169.20 and 697.39 is: 1,045.18

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.15 : 1,169.20 = 697.39 : x
  2. Step 2: Convert to fraction form
    780.15/1,169.20 = 697.39/x
  3. Step 3: Cross multiply
    780.15x = 1,169.20 × 697.39
  4. Step 4: Simplify right side
    780.15x = 815,392.91
  5. Step 5: Solve for x
    x = 815,392.91/780.15
  6. Step 6: Final answer
    x = 1,045.18

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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.