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Finding the Fourth Proportional to 72.90, 100.70 and 58.18

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Solution

The fourth proportional to 72.90, 100.70 and 58.18 is: 80.37

Step by Step Solution

  1. Step 1: Write the proportion equation
    72.90 : 100.70 = 58.18 : x
  2. Step 2: Convert to fraction form
    72.90/100.70 = 58.18/x
  3. Step 3: Cross multiply
    72.90x = 100.70 × 58.18
  4. Step 4: Simplify right side
    72.90x = 5,858.73
  5. Step 5: Solve for x
    x = 5,858.73/72.90
  6. Step 6: Final answer
    x = 80.37

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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.