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Finding the Fourth Proportional to 39.30, 54.14 and 31.10

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Solution

The fourth proportional to 39.30, 54.14 and 31.10 is: 42.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.30 : 54.14 = 31.10 : x
  2. Step 2: Convert to fraction form
    39.30/54.14 = 31.10/x
  3. Step 3: Cross multiply
    39.30x = 54.14 × 31.10
  4. Step 4: Simplify right side
    39.30x = 1,683.75
  5. Step 5: Solve for x
    x = 1,683.75/39.30
  6. Step 6: Final answer
    x = 42.84

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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.