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Finding the Fourth Proportional to 43.15, 64.70 and 21.49

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Solution

The fourth proportional to 43.15, 64.70 and 21.49 is: 32.22

Step by Step Solution

  1. Step 1: Write the proportion equation
    43.15 : 64.70 = 21.49 : x
  2. Step 2: Convert to fraction form
    43.15/64.70 = 21.49/x
  3. Step 3: Cross multiply
    43.15x = 64.70 × 21.49
  4. Step 4: Simplify right side
    43.15x = 1,390.40
  5. Step 5: Solve for x
    x = 1,390.40/43.15
  6. Step 6: Final answer
    x = 32.22

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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.