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Finding the Fourth Proportional to 52.80, 78.96 and 39.92

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Solution

The fourth proportional to 52.80, 78.96 and 39.92 is: 59.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.80 : 78.96 = 39.92 : x
  2. Step 2: Convert to fraction form
    52.80/78.96 = 39.92/x
  3. Step 3: Cross multiply
    52.80x = 78.96 × 39.92
  4. Step 4: Simplify right side
    52.80x = 3,152.08
  5. Step 5: Solve for x
    x = 3,152.08/52.80
  6. Step 6: Final answer
    x = 59.70

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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.