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Finding the Fourth Proportional to 125.12, 172.42 and 90.09

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Solution

The fourth proportional to 125.12, 172.42 and 90.09 is: 124.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    125.12 : 172.42 = 90.09 : x
  2. Step 2: Convert to fraction form
    125.12/172.42 = 90.09/x
  3. Step 3: Cross multiply
    125.12x = 172.42 × 90.09
  4. Step 4: Simplify right side
    125.12x = 15,533.09
  5. Step 5: Solve for x
    x = 15,533.09/125.12
  6. Step 6: Final answer
    x = 124.14

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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.