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Finding the Fourth Proportional to 65.38, 90.31 and 59.31

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Solution

The fourth proportional to 65.38, 90.31 and 59.31 is: 81.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    65.38 : 90.31 = 59.31 : x
  2. Step 2: Convert to fraction form
    65.38/90.31 = 59.31/x
  3. Step 3: Cross multiply
    65.38x = 90.31 × 59.31
  4. Step 4: Simplify right side
    65.38x = 5,356.29
  5. Step 5: Solve for x
    x = 5,356.29/65.38
  6. Step 6: Final answer
    x = 81.93

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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.