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Finding the Fourth Proportional to 287.58, 431.30 and 82.14

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Solution

The fourth proportional to 287.58, 431.30 and 82.14 is: 123.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.58 : 431.30 = 82.14 : x
  2. Step 2: Convert to fraction form
    287.58/431.30 = 82.14/x
  3. Step 3: Cross multiply
    287.58x = 431.30 × 82.14
  4. Step 4: Simplify right side
    287.58x = 35,426.98
  5. Step 5: Solve for x
    x = 35,426.98/287.58
  6. Step 6: Final answer
    x = 123.19

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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.