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Finding the Fourth Proportional to 287.68, 431.26 and 131.40

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Solution

The fourth proportional to 287.68, 431.26 and 131.40 is: 196.98

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.68 : 431.26 = 131.40 : x
  2. Step 2: Convert to fraction form
    287.68/431.26 = 131.40/x
  3. Step 3: Cross multiply
    287.68x = 431.26 × 131.40
  4. Step 4: Simplify right side
    287.68x = 56,667.56
  5. Step 5: Solve for x
    x = 56,667.56/287.68
  6. Step 6: Final answer
    x = 196.98

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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.