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Finding the Fourth Proportional to 90.71, 135.40 and 83.49

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Solution

The fourth proportional to 90.71, 135.40 and 83.49 is: 124.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.71 : 135.40 = 83.49 : x
  2. Step 2: Convert to fraction form
    90.71/135.40 = 83.49/x
  3. Step 3: Cross multiply
    90.71x = 135.40 × 83.49
  4. Step 4: Simplify right side
    90.71x = 11,304.55
  5. Step 5: Solve for x
    x = 11,304.55/90.71
  6. Step 6: Final answer
    x = 124.62

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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.