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Finding the Fourth Proportional to 72.30, 108.51 and 66.40

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Solution

The fourth proportional to 72.30, 108.51 and 66.40 is: 99.66

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.30 : 108.51 = 66.40 : x
  2. Step 2: Convert to fraction form
    72.30/108.51 = 66.40/x
  3. Step 3: Cross multiply
    72.30x = 108.51 × 66.40
  4. Step 4: Simplify right side
    72.30x = 7,205.06
  5. Step 5: Solve for x
    x = 7,205.06/72.30
  6. Step 6: Final answer
    x = 99.66

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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.