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Finding the Fourth Proportional to 30.51, 42.09 and 20.16

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Solution

The fourth proportional to 30.51, 42.09 and 20.16 is: 27.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    30.51 : 42.09 = 20.16 : x
  2. Step 2: Convert to fraction form
    30.51/42.09 = 20.16/x
  3. Step 3: Cross multiply
    30.51x = 42.09 × 20.16
  4. Step 4: Simplify right side
    30.51x = 848.53
  5. Step 5: Solve for x
    x = 848.53/30.51
  6. Step 6: Final answer
    x = 27.81

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.