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Finding the Fourth Proportional to 156.21, 215.50 and 125.20

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Solution

The fourth proportional to 156.21, 215.50 and 125.20 is: 172.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    156.21 : 215.50 = 125.20 : x
  2. Step 2: Convert to fraction form
    156.21/215.50 = 125.20/x
  3. Step 3: Cross multiply
    156.21x = 215.50 × 125.20
  4. Step 4: Simplify right side
    156.21x = 26,980.60
  5. Step 5: Solve for x
    x = 26,980.60/156.21
  6. Step 6: Final answer
    x = 172.72

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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.