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Finding the Fourth Proportional to 207.60, 286.55 and 128.98

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Solution

The fourth proportional to 207.60, 286.55 and 128.98 is: 178.03

Step by Step Solution

  1. Step 1: Write the proportion equation
    207.60 : 286.55 = 128.98 : x
  2. Step 2: Convert to fraction form
    207.60/286.55 = 128.98/x
  3. Step 3: Cross multiply
    207.60x = 286.55 × 128.98
  4. Step 4: Simplify right side
    207.60x = 36,959.22
  5. Step 5: Solve for x
    x = 36,959.22/207.60
  6. Step 6: Final answer
    x = 178.03

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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.