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Finding the Fourth Proportional to 202.57, 279.38 and 128.72

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Solution

The fourth proportional to 202.57, 279.38 and 128.72 is: 177.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    202.57 : 279.38 = 128.72 : x
  2. Step 2: Convert to fraction form
    202.57/279.38 = 128.72/x
  3. Step 3: Cross multiply
    202.57x = 279.38 × 128.72
  4. Step 4: Simplify right side
    202.57x = 35,962.81
  5. Step 5: Solve for x
    x = 35,962.81/202.57
  6. Step 6: Final answer
    x = 177.53

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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.