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Finding the Fourth Proportional to 42.51, 63.80 and 21.93

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Solution

The fourth proportional to 42.51, 63.80 and 21.93 is: 32.91

Step by Step Solution

  1. Step 1: Write the proportion equation
    42.51 : 63.80 = 21.93 : x
  2. Step 2: Convert to fraction form
    42.51/63.80 = 21.93/x
  3. Step 3: Cross multiply
    42.51x = 63.80 × 21.93
  4. Step 4: Simplify right side
    42.51x = 1,399.13
  5. Step 5: Solve for x
    x = 1,399.13/42.51
  6. Step 6: Final answer
    x = 32.91

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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.