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Finding the Fourth Proportional to 90.15, 124.40 and 55.18

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Solution

The fourth proportional to 90.15, 124.40 and 55.18 is: 76.14

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.15 : 124.40 = 55.18 : x
  2. Step 2: Convert to fraction form
    90.15/124.40 = 55.18/x
  3. Step 3: Cross multiply
    90.15x = 124.40 × 55.18
  4. Step 4: Simplify right side
    90.15x = 6,863.77
  5. Step 5: Solve for x
    x = 6,863.77/90.15
  6. Step 6: Final answer
    x = 76.14

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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.