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Finding the Fourth Proportional to 64.78, 97.31 and 40.47

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Solution

The fourth proportional to 64.78, 97.31 and 40.47 is: 60.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.78 : 97.31 = 40.47 : x
  2. Step 2: Convert to fraction form
    64.78/97.31 = 40.47/x
  3. Step 3: Cross multiply
    64.78x = 97.31 × 40.47
  4. Step 4: Simplify right side
    64.78x = 3,938.14
  5. Step 5: Solve for x
    x = 3,938.14/64.78
  6. Step 6: Final answer
    x = 60.79

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.