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Finding the Fourth Proportional to 253.11, 379.70 and 79.80

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Solution

The fourth proportional to 253.11, 379.70 and 79.80 is: 119.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    253.11 : 379.70 = 79.80 : x
  2. Step 2: Convert to fraction form
    253.11/379.70 = 79.80/x
  3. Step 3: Cross multiply
    253.11x = 379.70 × 79.80
  4. Step 4: Simplify right side
    253.11x = 30,300.06
  5. Step 5: Solve for x
    x = 30,300.06/253.11
  6. Step 6: Final answer
    x = 119.71

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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.