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Finding the Fourth Proportional to 89.40, 133.55 and 71.38

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Solution

The fourth proportional to 89.40, 133.55 and 71.38 is: 106.63

Step by Step Solution

  1. Step 1: Write the proportion equation
    89.40 : 133.55 = 71.38 : x
  2. Step 2: Convert to fraction form
    89.40/133.55 = 71.38/x
  3. Step 3: Cross multiply
    89.40x = 133.55 × 71.38
  4. Step 4: Simplify right side
    89.40x = 9,532.80
  5. Step 5: Solve for x
    x = 9,532.80/89.40
  6. Step 6: Final answer
    x = 106.63

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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.