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Finding the Fourth Proportional to 90.40, 135.59 and 39.05

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Solution

The fourth proportional to 90.40, 135.59 and 39.05 is: 58.57

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.40 : 135.59 = 39.05 : x
  2. Step 2: Convert to fraction form
    90.40/135.59 = 39.05/x
  3. Step 3: Cross multiply
    90.40x = 135.59 × 39.05
  4. Step 4: Simplify right side
    90.40x = 5,294.79
  5. Step 5: Solve for x
    x = 5,294.79/90.40
  6. Step 6: Final answer
    x = 58.57

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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.