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Finding the Fourth Proportional to 90.19, 135.02 and 78.91

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Solution

The fourth proportional to 90.19, 135.02 and 78.91 is: 118.13

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.19 : 135.02 = 78.91 : x
  2. Step 2: Convert to fraction form
    90.19/135.02 = 78.91/x
  3. Step 3: Cross multiply
    90.19x = 135.02 × 78.91
  4. Step 4: Simplify right side
    90.19x = 10,654.43
  5. Step 5: Solve for x
    x = 10,654.43/90.19
  6. Step 6: Final answer
    x = 118.13

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These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.