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Finding the Fourth Proportional to 90.29, 124.35 and 85.66

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Solution

The fourth proportional to 90.29, 124.35 and 85.66 is: 117.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.29 : 124.35 = 85.66 : x
  2. Step 2: Convert to fraction form
    90.29/124.35 = 85.66/x
  3. Step 3: Cross multiply
    90.29x = 124.35 × 85.66
  4. Step 4: Simplify right side
    90.29x = 10,651.82
  5. Step 5: Solve for x
    x = 10,651.82/90.29
  6. Step 6: Final answer
    x = 117.97

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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.