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Finding the Fourth Proportional to 199.50, 299.40 and 77.78

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Solution

The fourth proportional to 199.50, 299.40 and 77.78 is: 116.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    199.50 : 299.40 = 77.78 : x
  2. Step 2: Convert to fraction form
    199.50/299.40 = 77.78/x
  3. Step 3: Cross multiply
    199.50x = 299.40 × 77.78
  4. Step 4: Simplify right side
    199.50x = 23,285.84
  5. Step 5: Solve for x
    x = 23,285.84/199.50
  6. Step 6: Final answer
    x = 116.72

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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.