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Finding the Fourth Proportional to 64.77, 89.84 and 61.31

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Solution

The fourth proportional to 64.77, 89.84 and 61.31 is: 85.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.77 : 89.84 = 61.31 : x
  2. Step 2: Convert to fraction form
    64.77/89.84 = 61.31/x
  3. Step 3: Cross multiply
    64.77x = 89.84 × 61.31
  4. Step 4: Simplify right side
    64.77x = 5,508.09
  5. Step 5: Solve for x
    x = 5,508.09/64.77
  6. Step 6: Final answer
    x = 85.04

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.