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Finding the Fourth Proportional to 55.42, 83.08 and 21.18

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Solution

The fourth proportional to 55.42, 83.08 and 21.18 is: 31.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    55.42 : 83.08 = 21.18 : x
  2. Step 2: Convert to fraction form
    55.42/83.08 = 21.18/x
  3. Step 3: Cross multiply
    55.42x = 83.08 × 21.18
  4. Step 4: Simplify right side
    55.42x = 1,759.63
  5. Step 5: Solve for x
    x = 1,759.63/55.42
  6. Step 6: Final answer
    x = 31.75

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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.