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Finding the Fourth Proportional to 288.12, 431.72 and 172.28

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Solution

The fourth proportional to 288.12, 431.72 and 172.28 is: 258.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    288.12 : 431.72 = 172.28 : x
  2. Step 2: Convert to fraction form
    288.12/431.72 = 172.28/x
  3. Step 3: Cross multiply
    288.12x = 431.72 × 172.28
  4. Step 4: Simplify right side
    288.12x = 74,376.72
  5. Step 5: Solve for x
    x = 74,376.72/288.12
  6. Step 6: Final answer
    x = 258.14

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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.