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Finding the Fourth Proportional to 90.33, 135.51 and 42.21

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Solution

The fourth proportional to 90.33, 135.51 and 42.21 is: 63.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    90.33 : 135.51 = 42.21 : x
  2. Step 2: Convert to fraction form
    90.33/135.51 = 42.21/x
  3. Step 3: Cross multiply
    90.33x = 135.51 × 42.21
  4. Step 4: Simplify right side
    90.33x = 5,719.88
  5. Step 5: Solve for x
    x = 5,719.88/90.33
  6. Step 6: Final answer
    x = 63.32

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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.