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Finding the Fourth Proportional to 286.39, 431.35 and 261.42

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Solution

The fourth proportional to 286.39, 431.35 and 261.42 is: 393.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    286.39 : 431.35 = 261.42 : x
  2. Step 2: Convert to fraction form
    286.39/431.35 = 261.42/x
  3. Step 3: Cross multiply
    286.39x = 431.35 × 261.42
  4. Step 4: Simplify right side
    286.39x = 112,763.52
  5. Step 5: Solve for x
    x = 112,763.52/286.39
  6. Step 6: Final answer
    x = 393.74

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.