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Finding the Fourth Proportional to 73.80, 101.70 and 72.90

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Solution

The fourth proportional to 73.80, 101.70 and 72.90 is: 100.46

Step by Step Solution

  1. Step 1: Write the proportion equation
    73.80 : 101.70 = 72.90 : x
  2. Step 2: Convert to fraction form
    73.80/101.70 = 72.90/x
  3. Step 3: Cross multiply
    73.80x = 101.70 × 72.90
  4. Step 4: Simplify right side
    73.80x = 7,413.93
  5. Step 5: Solve for x
    x = 7,413.93/73.80
  6. Step 6: Final answer
    x = 100.46

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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.