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Finding the Fourth Proportional to 287.89, 431.62 and 143.31

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Solution

The fourth proportional to 287.89, 431.62 and 143.31 is: 214.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.89 : 431.62 = 143.31 : x
  2. Step 2: Convert to fraction form
    287.89/431.62 = 143.31/x
  3. Step 3: Cross multiply
    287.89x = 431.62 × 143.31
  4. Step 4: Simplify right side
    287.89x = 61,855.46
  5. Step 5: Solve for x
    x = 61,855.46/287.89
  6. Step 6: Final answer
    x = 214.86

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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.