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Finding the Fourth Proportional to 71.40, 107.15 and 51.15

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Solution

The fourth proportional to 71.40, 107.15 and 51.15 is: 76.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    71.40 : 107.15 = 51.15 : x
  2. Step 2: Convert to fraction form
    71.40/107.15 = 51.15/x
  3. Step 3: Cross multiply
    71.40x = 107.15 × 51.15
  4. Step 4: Simplify right side
    71.40x = 5,480.47
  5. Step 5: Solve for x
    x = 5,480.47/71.40
  6. Step 6: Final answer
    x = 76.76

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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.