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Finding the Fourth Proportional to 128.94, 193.42 and 90.44

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Solution

The fourth proportional to 128.94, 193.42 and 90.44 is: 135.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    128.94 : 193.42 = 90.44 : x
  2. Step 2: Convert to fraction form
    128.94/193.42 = 90.44/x
  3. Step 3: Cross multiply
    128.94x = 193.42 × 90.44
  4. Step 4: Simplify right side
    128.94x = 17,492.90
  5. Step 5: Solve for x
    x = 17,492.90/128.94
  6. Step 6: Final answer
    x = 135.67

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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.