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Finding the Fourth Proportional to 78.62, 108.51 and 65.49

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Solution

The fourth proportional to 78.62, 108.51 and 65.49 is: 90.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.62 : 108.51 = 65.49 : x
  2. Step 2: Convert to fraction form
    78.62/108.51 = 65.49/x
  3. Step 3: Cross multiply
    78.62x = 108.51 × 65.49
  4. Step 4: Simplify right side
    78.62x = 7,105.67
  5. Step 5: Solve for x
    x = 7,105.67/78.62
  6. Step 6: Final answer
    x = 90.38

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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.