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Finding the Fourth Proportional to 61.80, 85.35 and 47.10

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Solution

The fourth proportional to 61.80, 85.35 and 47.10 is: 65.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    61.80 : 85.35 = 47.10 : x
  2. Step 2: Convert to fraction form
    61.80/85.35 = 47.10/x
  3. Step 3: Cross multiply
    61.80x = 85.35 × 47.10
  4. Step 4: Simplify right side
    61.80x = 4,019.99
  5. Step 5: Solve for x
    x = 4,019.99/61.80
  6. Step 6: Final answer
    x = 65.05

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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.