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Finding the Fourth Proportional to 61.80, 85.39 and 48.09

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Solution

The fourth proportional to 61.80, 85.39 and 48.09 is: 66.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.80 : 85.39 = 48.09 : x
  2. Step 2: Convert to fraction form
    61.80/85.39 = 48.09/x
  3. Step 3: Cross multiply
    61.80x = 85.39 × 48.09
  4. Step 4: Simplify right side
    61.80x = 4,106.61
  5. Step 5: Solve for x
    x = 4,106.61/61.80
  6. Step 6: Final answer
    x = 66.45

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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.