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Finding the Fourth Proportional to 75.40, 112.31 and 71.89

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Solution

The fourth proportional to 75.40, 112.31 and 71.89 is: 107.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.40 : 112.31 = 71.89 : x
  2. Step 2: Convert to fraction form
    75.40/112.31 = 71.89/x
  3. Step 3: Cross multiply
    75.40x = 112.31 × 71.89
  4. Step 4: Simplify right side
    75.40x = 8,073.97
  5. Step 5: Solve for x
    x = 8,073.97/75.40
  6. Step 6: Final answer
    x = 107.08

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.