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Finding the Fourth Proportional to 499.78, 749.78 and 191.78

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Solution

The fourth proportional to 499.78, 749.78 and 191.78 is: 287.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    499.78 : 749.78 = 191.78 : x
  2. Step 2: Convert to fraction form
    499.78/749.78 = 191.78/x
  3. Step 3: Cross multiply
    499.78x = 749.78 × 191.78
  4. Step 4: Simplify right side
    499.78x = 143,792.71
  5. Step 5: Solve for x
    x = 143,792.71/499.78
  6. Step 6: Final answer
    x = 287.71

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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.