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Finding the Fourth Proportional to 108.31, 162.37 and 39.78

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Solution

The fourth proportional to 108.31, 162.37 and 39.78 is: 59.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    108.31 : 162.37 = 39.78 : x
  2. Step 2: Convert to fraction form
    108.31/162.37 = 39.78/x
  3. Step 3: Cross multiply
    108.31x = 162.37 × 39.78
  4. Step 4: Simplify right side
    108.31x = 6,459.29
  5. Step 5: Solve for x
    x = 6,459.29/108.31
  6. Step 6: Final answer
    x = 59.64

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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.