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Finding the Fourth Proportional to 253.78, 380.57 and 99.70

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Solution

The fourth proportional to 253.78, 380.57 and 99.70 is: 149.51

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.78 : 380.57 = 99.70 : x
  2. Step 2: Convert to fraction form
    253.78/380.57 = 99.70/x
  3. Step 3: Cross multiply
    253.78x = 380.57 × 99.70
  4. Step 4: Simplify right side
    253.78x = 37,942.83
  5. Step 5: Solve for x
    x = 37,942.83/253.78
  6. Step 6: Final answer
    x = 149.51

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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.