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Finding the Fourth Proportional to 90.45, 135.91 and 70.41

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Solution

The fourth proportional to 90.45, 135.91 and 70.41 is: 105.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.45 : 135.91 = 70.41 : x
  2. Step 2: Convert to fraction form
    90.45/135.91 = 70.41/x
  3. Step 3: Cross multiply
    90.45x = 135.91 × 70.41
  4. Step 4: Simplify right side
    90.45x = 9,569.42
  5. Step 5: Solve for x
    x = 9,569.42/90.45
  6. Step 6: Final answer
    x = 105.80

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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.