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Finding the Fourth Proportional to 31.97, 43.76 and 30.80

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Solution

The fourth proportional to 31.97, 43.76 and 30.80 is: 42.16

Step by Step Solution

  1. Step 1: Write the proportion equation
    31.97 : 43.76 = 30.80 : x
  2. Step 2: Convert to fraction form
    31.97/43.76 = 30.80/x
  3. Step 3: Cross multiply
    31.97x = 43.76 × 30.80
  4. Step 4: Simplify right side
    31.97x = 1,347.81
  5. Step 5: Solve for x
    x = 1,347.81/31.97
  6. Step 6: Final answer
    x = 42.16

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Why These Related Problems?

These problems maintain the same ratio (1.37) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.