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Finding the Fourth Proportional to 64.78, 97.20 and 30.56

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Solution

The fourth proportional to 64.78, 97.20 and 30.56 is: 45.85

Step by Step Solution

  1. Step 1: Write the proportion equation
    64.78 : 97.20 = 30.56 : x
  2. Step 2: Convert to fraction form
    64.78/97.20 = 30.56/x
  3. Step 3: Cross multiply
    64.78x = 97.20 × 30.56
  4. Step 4: Simplify right side
    64.78x = 2,969.95
  5. Step 5: Solve for x
    x = 2,969.95/64.78
  6. Step 6: Final answer
    x = 45.85

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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.