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Finding the Fourth Proportional to 81.48, 112.61 and 65.08

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Solution

The fourth proportional to 81.48, 112.61 and 65.08 is: 89.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    81.48 : 112.61 = 65.08 : x
  2. Step 2: Convert to fraction form
    81.48/112.61 = 65.08/x
  3. Step 3: Cross multiply
    81.48x = 112.61 × 65.08
  4. Step 4: Simplify right side
    81.48x = 7,328.96
  5. Step 5: Solve for x
    x = 7,328.96/81.48
  6. Step 6: Final answer
    x = 89.94

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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.