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Finding the Fourth Proportional to 90.65, 135.88 and 35.78

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Solution

The fourth proportional to 90.65, 135.88 and 35.78 is: 53.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.65 : 135.88 = 35.78 : x
  2. Step 2: Convert to fraction form
    90.65/135.88 = 35.78/x
  3. Step 3: Cross multiply
    90.65x = 135.88 × 35.78
  4. Step 4: Simplify right side
    90.65x = 4,861.02
  5. Step 5: Solve for x
    x = 4,861.02/90.65
  6. Step 6: Final answer
    x = 53.62

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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.