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Finding the Fourth Proportional to 781.40, 1,076.14 and 764.39

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Solution

The fourth proportional to 781.40, 1,076.14 and 764.39 is: 1,052.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    781.40 : 1,076.14 = 764.39 : x
  2. Step 2: Convert to fraction form
    781.40/1,076.14 = 764.39/x
  3. Step 3: Cross multiply
    781.40x = 1,076.14 × 764.39
  4. Step 4: Simplify right side
    781.40x = 822,590.65
  5. Step 5: Solve for x
    x = 822,590.65/781.40
  6. Step 6: Final answer
    x = 1,052.71

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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.