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Finding the Fourth Proportional to 287.79, 431.64 and 82.38

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Solution

The fourth proportional to 287.79, 431.64 and 82.38 is: 123.56

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.79 : 431.64 = 82.38 : x
  2. Step 2: Convert to fraction form
    287.79/431.64 = 82.38/x
  3. Step 3: Cross multiply
    287.79x = 431.64 × 82.38
  4. Step 4: Simplify right side
    287.79x = 35,558.50
  5. Step 5: Solve for x
    x = 35,558.50/287.79
  6. Step 6: Final answer
    x = 123.56

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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.