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Finding the Fourth Proportional to 39.30, 54.30 and 39.00

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Solution

The fourth proportional to 39.30, 54.30 and 39.00 is: 53.88

Step by Step Solution

  1. Step 1: Write the proportion equation
    39.30 : 54.30 = 39.00 : x
  2. Step 2: Convert to fraction form
    39.30/54.30 = 39.00/x
  3. Step 3: Cross multiply
    39.30x = 54.30 × 39.00
  4. Step 4: Simplify right side
    39.30x = 2,117.42
  5. Step 5: Solve for x
    x = 2,117.42/39.30
  6. Step 6: Final answer
    x = 53.88

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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.