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Finding the Fourth Proportional to 156.25, 215.32 and 138.63

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Solution

The fourth proportional to 156.25, 215.32 and 138.63 is: 191.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.25 : 215.32 = 138.63 : x
  2. Step 2: Convert to fraction form
    156.25/215.32 = 138.63/x
  3. Step 3: Cross multiply
    156.25x = 215.32 × 138.63
  4. Step 4: Simplify right side
    156.25x = 29,849.81
  5. Step 5: Solve for x
    x = 29,849.81/156.25
  6. Step 6: Final answer
    x = 191.04

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.