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Finding the Fourth Proportional to 78.30, 108.06 and 49.20

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Solution

The fourth proportional to 78.30, 108.06 and 49.20 is: 67.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    78.30 : 108.06 = 49.20 : x
  2. Step 2: Convert to fraction form
    78.30/108.06 = 49.20/x
  3. Step 3: Cross multiply
    78.30x = 108.06 × 49.20
  4. Step 4: Simplify right side
    78.30x = 5,316.55
  5. Step 5: Solve for x
    x = 5,316.55/78.30
  6. Step 6: Final answer
    x = 67.90

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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.