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Finding the Fourth Proportional to 109.17, 150.54 and 90.72

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Solution

The fourth proportional to 109.17, 150.54 and 90.72 is: 125.10

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.17 : 150.54 = 90.72 : x
  2. Step 2: Convert to fraction form
    109.17/150.54 = 90.72/x
  3. Step 3: Cross multiply
    109.17x = 150.54 × 90.72
  4. Step 4: Simplify right side
    109.17x = 13,656.99
  5. Step 5: Solve for x
    x = 13,656.99/109.17
  6. Step 6: Final answer
    x = 125.10

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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.