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Finding the Fourth Proportional to 90.05, 134.40 and 89.19

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Solution

The fourth proportional to 90.05, 134.40 and 89.19 is: 133.12

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.05 : 134.40 = 89.19 : x
  2. Step 2: Convert to fraction form
    90.05/134.40 = 89.19/x
  3. Step 3: Cross multiply
    90.05x = 134.40 × 89.19
  4. Step 4: Simplify right side
    90.05x = 11,987.14
  5. Step 5: Solve for x
    x = 11,987.14/90.05
  6. Step 6: Final answer
    x = 133.12

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.