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Finding the Fourth Proportional to 78.73, 108.60 and 64.15

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Solution

The fourth proportional to 78.73, 108.60 and 64.15 is: 88.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.73 : 108.60 = 64.15 : x
  2. Step 2: Convert to fraction form
    78.73/108.60 = 64.15/x
  3. Step 3: Cross multiply
    78.73x = 108.60 × 64.15
  4. Step 4: Simplify right side
    78.73x = 6,966.69
  5. Step 5: Solve for x
    x = 6,966.69/78.73
  6. Step 6: Final answer
    x = 88.49

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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.