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Finding the Fourth Proportional to 61.50, 84.90 and 38.50

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Solution

The fourth proportional to 61.50, 84.90 and 38.50 is: 53.15

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.50 : 84.90 = 38.50 : x
  2. Step 2: Convert to fraction form
    61.50/84.90 = 38.50/x
  3. Step 3: Cross multiply
    61.50x = 84.90 × 38.50
  4. Step 4: Simplify right side
    61.50x = 3,268.65
  5. Step 5: Solve for x
    x = 3,268.65/61.50
  6. Step 6: Final answer
    x = 53.15

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.