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Finding the Fourth Proportional to 109.86, 151.34 and 90.12

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Solution

The fourth proportional to 109.86, 151.34 and 90.12 is: 124.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    109.86 : 151.34 = 90.12 : x
  2. Step 2: Convert to fraction form
    109.86/151.34 = 90.12/x
  3. Step 3: Cross multiply
    109.86x = 151.34 × 90.12
  4. Step 4: Simplify right side
    109.86x = 13,638.76
  5. Step 5: Solve for x
    x = 13,638.76/109.86
  6. Step 6: Final answer
    x = 124.15

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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.