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Finding the Fourth Proportional to 65.90, 98.90 and 38.86

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Solution

The fourth proportional to 65.90, 98.90 and 38.86 is: 58.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.90 : 98.90 = 38.86 : x
  2. Step 2: Convert to fraction form
    65.90/98.90 = 38.86/x
  3. Step 3: Cross multiply
    65.90x = 98.90 × 38.86
  4. Step 4: Simplify right side
    65.90x = 3,843.25
  5. Step 5: Solve for x
    x = 3,843.25/65.90
  6. Step 6: Final answer
    x = 58.32

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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.