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Finding the Fourth Proportional to 90.81, 125.33 and 71.55

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Solution

The fourth proportional to 90.81, 125.33 and 71.55 is: 98.74

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.81 : 125.33 = 71.55 : x
  2. Step 2: Convert to fraction form
    90.81/125.33 = 71.55/x
  3. Step 3: Cross multiply
    90.81x = 125.33 × 71.55
  4. Step 4: Simplify right side
    90.81x = 8,967.00
  5. Step 5: Solve for x
    x = 8,967.00/90.81
  6. Step 6: Final answer
    x = 98.74

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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.