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Finding the Fourth Proportional to 71.80, 107.52 and 39.70

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Solution

The fourth proportional to 71.80, 107.52 and 39.70 is: 59.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.80 : 107.52 = 39.70 : x
  2. Step 2: Convert to fraction form
    71.80/107.52 = 39.70/x
  3. Step 3: Cross multiply
    71.80x = 107.52 × 39.70
  4. Step 4: Simplify right side
    71.80x = 4,268.54
  5. Step 5: Solve for x
    x = 4,268.54/71.80
  6. Step 6: Final answer
    x = 59.45

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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.