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Finding the Fourth Proportional to 47.31, 71.30 and 42.86

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Solution

The fourth proportional to 47.31, 71.30 and 42.86 is: 64.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    47.31 : 71.30 = 42.86 : x
  2. Step 2: Convert to fraction form
    47.31/71.30 = 42.86/x
  3. Step 3: Cross multiply
    47.31x = 71.30 × 42.86
  4. Step 4: Simplify right side
    47.31x = 3,055.35
  5. Step 5: Solve for x
    x = 3,055.35/47.31
  6. Step 6: Final answer
    x = 64.58

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Why These Related Problems?

These problems maintain the same ratio (1.51) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.