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Finding the Fourth Proportional to 785.78, 1,178.71 and 265.80

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Solution

The fourth proportional to 785.78, 1,178.71 and 265.80 is: 398.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    785.78 : 1,178.71 = 265.80 : x
  2. Step 2: Convert to fraction form
    785.78/1,178.71 = 265.80/x
  3. Step 3: Cross multiply
    785.78x = 1,178.71 × 265.80
  4. Step 4: Simplify right side
    785.78x = 313,301.12
  5. Step 5: Solve for x
    x = 313,301.12/785.78
  6. Step 6: Final answer
    x = 398.71

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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.