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Finding the Fourth Proportional to 71.82, 98.87 and 64.31

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Solution

The fourth proportional to 71.82, 98.87 and 64.31 is: 88.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.82 : 98.87 = 64.31 : x
  2. Step 2: Convert to fraction form
    71.82/98.87 = 64.31/x
  3. Step 3: Cross multiply
    71.82x = 98.87 × 64.31
  4. Step 4: Simplify right side
    71.82x = 6,357.51
  5. Step 5: Solve for x
    x = 6,357.51/71.82
  6. Step 6: Final answer
    x = 88.52

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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.