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Finding the Fourth Proportional to 287.86, 431.92 and 172.30

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Solution

The fourth proportional to 287.86, 431.92 and 172.30 is: 258.53

Step by Step Solution

  1. Step 1: Write the proportion equation
    287.86 : 431.92 = 172.30 : x
  2. Step 2: Convert to fraction form
    287.86/431.92 = 172.30/x
  3. Step 3: Cross multiply
    287.86x = 431.92 × 172.30
  4. Step 4: Simplify right side
    287.86x = 74,419.82
  5. Step 5: Solve for x
    x = 74,419.82/287.86
  6. Step 6: Final answer
    x = 258.53

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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.