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Finding the Fourth Proportional to 287.38, 431.10 and 89.71

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Solution

The fourth proportional to 287.38, 431.10 and 89.71 is: 134.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.38 : 431.10 = 89.71 : x
  2. Step 2: Convert to fraction form
    287.38/431.10 = 89.71/x
  3. Step 3: Cross multiply
    287.38x = 431.10 × 89.71
  4. Step 4: Simplify right side
    287.38x = 38,673.71
  5. Step 5: Solve for x
    x = 38,673.71/287.38
  6. Step 6: Final answer
    x = 134.57

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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.