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Finding the Fourth Proportional to 266.60, 399.90 and 81.50

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Solution

The fourth proportional to 266.60, 399.90 and 81.50 is: 122.25

Step by Step Solution

  1. Step 1: Write the proportion equation
    266.60 : 399.90 = 81.50 : x
  2. Step 2: Convert to fraction form
    266.60/399.90 = 81.50/x
  3. Step 3: Cross multiply
    266.60x = 399.90 × 81.50
  4. Step 4: Simplify right side
    266.60x = 32,592.62
  5. Step 5: Solve for x
    x = 32,592.62/266.60
  6. Step 6: Final answer
    x = 122.25

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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.