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Finding the Fourth Proportional to 57.09, 78.79 and 31.22

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Solution

The fourth proportional to 57.09, 78.79 and 31.22 is: 43.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    57.09 : 78.79 = 31.22 : x
  2. Step 2: Convert to fraction form
    57.09/78.79 = 31.22/x
  3. Step 3: Cross multiply
    57.09x = 78.79 × 31.22
  4. Step 4: Simplify right side
    57.09x = 2,459.71
  5. Step 5: Solve for x
    x = 2,459.71/57.09
  6. Step 6: Final answer
    x = 43.08

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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.