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Finding the Fourth Proportional to 55.90, 83.80 and 28.50

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Solution

The fourth proportional to 55.90, 83.80 and 28.50 is: 42.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.90 : 83.80 = 28.50 : x
  2. Step 2: Convert to fraction form
    55.90/83.80 = 28.50/x
  3. Step 3: Cross multiply
    55.90x = 83.80 × 28.50
  4. Step 4: Simplify right side
    55.90x = 2,388.30
  5. Step 5: Solve for x
    x = 2,388.30/55.90
  6. Step 6: Final answer
    x = 42.72

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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.