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Finding the Fourth Proportional to 38.90, 58.31 and 28.64

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Solution

The fourth proportional to 38.90, 58.31 and 28.64 is: 42.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    38.90 : 58.31 = 28.64 : x
  2. Step 2: Convert to fraction form
    38.90/58.31 = 28.64/x
  3. Step 3: Cross multiply
    38.90x = 58.31 × 28.64
  4. Step 4: Simplify right side
    38.90x = 1,669.64
  5. Step 5: Solve for x
    x = 1,669.64/38.90
  6. Step 6: Final answer
    x = 42.93

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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.