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Finding the Fourth Proportional to 52.30, 78.40 and 21.89

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Solution

The fourth proportional to 52.30, 78.40 and 21.89 is: 32.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    52.30 : 78.40 = 21.89 : x
  2. Step 2: Convert to fraction form
    52.30/78.40 = 21.89/x
  3. Step 3: Cross multiply
    52.30x = 78.40 × 21.89
  4. Step 4: Simplify right side
    52.30x = 1,716.18
  5. Step 5: Solve for x
    x = 1,716.18/52.30
  6. Step 6: Final answer
    x = 32.81

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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.