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Finding the Fourth Proportional to 75.40, 112.89 and 57.28

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Solution

The fourth proportional to 75.40, 112.89 and 57.28 is: 85.76

Step by Step Solution

  1. Step 1: Write the proportion equation
    75.40 : 112.89 = 57.28 : x
  2. Step 2: Convert to fraction form
    75.40/112.89 = 57.28/x
  3. Step 3: Cross multiply
    75.40x = 112.89 × 57.28
  4. Step 4: Simplify right side
    75.40x = 6,466.34
  5. Step 5: Solve for x
    x = 6,466.34/75.40
  6. Step 6: Final answer
    x = 85.76

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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.