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Finding the Fourth Proportional to 65.40, 98.11 and 19.75

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Solution

The fourth proportional to 65.40, 98.11 and 19.75 is: 29.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.40 : 98.11 = 19.75 : x
  2. Step 2: Convert to fraction form
    65.40/98.11 = 19.75/x
  3. Step 3: Cross multiply
    65.40x = 98.11 × 19.75
  4. Step 4: Simplify right side
    65.40x = 1,937.91
  5. Step 5: Solve for x
    x = 1,937.91/65.40
  6. Step 6: Final answer
    x = 29.63

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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.