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Finding the Fourth Proportional to 78.67, 108.66 and 64.23

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Solution

The fourth proportional to 78.67, 108.66 and 64.23 is: 88.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.67 : 108.66 = 64.23 : x
  2. Step 2: Convert to fraction form
    78.67/108.66 = 64.23/x
  3. Step 3: Cross multiply
    78.67x = 108.66 × 64.23
  4. Step 4: Simplify right side
    78.67x = 6,979.23
  5. Step 5: Solve for x
    x = 6,979.23/78.67
  6. Step 6: Final answer
    x = 88.72

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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.