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Finding the Fourth Proportional to 120.08, 180 and 90.39

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Solution

The fourth proportional to 120.08, 180 and 90.39 is: 135.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    120.08 : 180 = 90.39 : x
  2. Step 2: Convert to fraction form
    120.08/180 = 90.39/x
  3. Step 3: Cross multiply
    120.08x = 180 × 90.39
  4. Step 4: Simplify right side
    120.08x = 16,270.20
  5. Step 5: Solve for x
    x = 16,270.20/120.08
  6. Step 6: Final answer
    x = 135.50

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1.5x scale

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.