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Finding the Fourth Proportional to 55.81, 83.72 and 21.57

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Solution

The fourth proportional to 55.81, 83.72 and 21.57 is: 32.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.81 : 83.72 = 21.57 : x
  2. Step 2: Convert to fraction form
    55.81/83.72 = 21.57/x
  3. Step 3: Cross multiply
    55.81x = 83.72 × 21.57
  4. Step 4: Simplify right side
    55.81x = 1,805.84
  5. Step 5: Solve for x
    x = 1,805.84/55.81
  6. Step 6: Final answer
    x = 32.36

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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.