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Finding the Fourth Proportional to 43.40, 65.10 and 21.72

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Solution

The fourth proportional to 43.40, 65.10 and 21.72 is: 32.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    43.40 : 65.10 = 21.72 : x
  2. Step 2: Convert to fraction form
    43.40/65.10 = 21.72/x
  3. Step 3: Cross multiply
    43.40x = 65.10 × 21.72
  4. Step 4: Simplify right side
    43.40x = 1,413.93
  5. Step 5: Solve for x
    x = 1,413.93/43.40
  6. Step 6: Final answer
    x = 32.58

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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.