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Finding the Fourth Proportional to 253.82, 380.92 and 99.78

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Solution

The fourth proportional to 253.82, 380.92 and 99.78 is: 149.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.82 : 380.92 = 99.78 : x
  2. Step 2: Convert to fraction form
    253.82/380.92 = 99.78/x
  3. Step 3: Cross multiply
    253.82x = 380.92 × 99.78
  4. Step 4: Simplify right side
    253.82x = 38,009.75
  5. Step 5: Solve for x
    x = 38,009.75/253.82
  6. Step 6: Final answer
    x = 149.75

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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.