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Finding the Fourth Proportional to 287.39, 431.06 and 92.40

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Solution

The fourth proportional to 287.39, 431.06 and 92.40 is: 138.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.39 : 431.06 = 92.40 : x
  2. Step 2: Convert to fraction form
    287.39/431.06 = 92.40/x
  3. Step 3: Cross multiply
    287.39x = 431.06 × 92.40
  4. Step 4: Simplify right side
    287.39x = 39,829.94
  5. Step 5: Solve for x
    x = 39,829.94/287.39
  6. Step 6: Final answer
    x = 138.59

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.