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Finding the Fourth Proportional to 72.75, 108.90 and 47.10

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Solution

The fourth proportional to 72.75, 108.90 and 47.10 is: 70.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.75 : 108.90 = 47.10 : x
  2. Step 2: Convert to fraction form
    72.75/108.90 = 47.10/x
  3. Step 3: Cross multiply
    72.75x = 108.90 × 47.10
  4. Step 4: Simplify right side
    72.75x = 5,129.19
  5. Step 5: Solve for x
    x = 5,129.19/72.75
  6. Step 6: Final answer
    x = 70.50

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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.