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Finding the Fourth Proportional to 65.84, 90.87 and 39.61

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Solution

The fourth proportional to 65.84, 90.87 and 39.61 is: 54.67

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.84 : 90.87 = 39.61 : x
  2. Step 2: Convert to fraction form
    65.84/90.87 = 39.61/x
  3. Step 3: Cross multiply
    65.84x = 90.87 × 39.61
  4. Step 4: Simplify right side
    65.84x = 3,599.62
  5. Step 5: Solve for x
    x = 3,599.62/65.84
  6. Step 6: Final answer
    x = 54.67

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.