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Finding the Fourth Proportional to 99.40, 149.21 and 89.18

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Solution

The fourth proportional to 99.40, 149.21 and 89.18 is: 133.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    99.40 : 149.21 = 89.18 : x
  2. Step 2: Convert to fraction form
    99.40/149.21 = 89.18/x
  3. Step 3: Cross multiply
    99.40x = 149.21 × 89.18
  4. Step 4: Simplify right side
    99.40x = 13,306.55
  5. Step 5: Solve for x
    x = 13,306.55/99.40
  6. Step 6: Final answer
    x = 133.87

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Why These Related Problems?

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