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Finding the Fourth Proportional to 202.56, 279.38 and 128.81

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Solution

The fourth proportional to 202.56, 279.38 and 128.81 is: 177.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    202.56 : 279.38 = 128.81 : x
  2. Step 2: Convert to fraction form
    202.56/279.38 = 128.81/x
  3. Step 3: Cross multiply
    202.56x = 279.38 × 128.81
  4. Step 4: Simplify right side
    202.56x = 35,984.90
  5. Step 5: Solve for x
    x = 35,984.90/202.56
  6. Step 6: Final answer
    x = 177.65

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.