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Finding the Fourth Proportional to 103.86, 155.10 and 90.18

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Solution

The fourth proportional to 103.86, 155.10 and 90.18 is: 134.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    103.86 : 155.10 = 90.18 : x
  2. Step 2: Convert to fraction form
    103.86/155.10 = 90.18/x
  3. Step 3: Cross multiply
    103.86x = 155.10 × 90.18
  4. Step 4: Simplify right side
    103.86x = 13,986.92
  5. Step 5: Solve for x
    x = 13,986.92/103.86
  6. Step 6: Final answer
    x = 134.67

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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.