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Finding the Fourth Proportional to 65.90, 91.13 and 59.15

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Solution

The fourth proportional to 65.90, 91.13 and 59.15 is: 81.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.90 : 91.13 = 59.15 : x
  2. Step 2: Convert to fraction form
    65.90/91.13 = 59.15/x
  3. Step 3: Cross multiply
    65.90x = 91.13 × 59.15
  4. Step 4: Simplify right side
    65.90x = 5,390.27
  5. Step 5: Solve for x
    x = 5,390.27/65.90
  6. Step 6: Final answer
    x = 81.79

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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.