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Finding the Fourth Proportional to 72.42, 108.03 and 66.21

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Solution

The fourth proportional to 72.42, 108.03 and 66.21 is: 98.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.42 : 108.03 = 66.21 : x
  2. Step 2: Convert to fraction form
    72.42/108.03 = 66.21/x
  3. Step 3: Cross multiply
    72.42x = 108.03 × 66.21
  4. Step 4: Simplify right side
    72.42x = 7,152.67
  5. Step 5: Solve for x
    x = 7,152.67/72.42
  6. Step 6: Final answer
    x = 98.77

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.