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Finding the Fourth Proportional to 202.61, 279.62 and 128.90

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Solution

The fourth proportional to 202.61, 279.62 and 128.90 is: 177.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    202.61 : 279.62 = 128.90 : x
  2. Step 2: Convert to fraction form
    202.61/279.62 = 128.90/x
  3. Step 3: Cross multiply
    202.61x = 279.62 × 128.90
  4. Step 4: Simplify right side
    202.61x = 36,043.02
  5. Step 5: Solve for x
    x = 36,043.02/202.61
  6. Step 6: Final answer
    x = 177.89

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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.