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Finding the Fourth Proportional to 228.31, 315.12 and 139.75

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Solution

The fourth proportional to 228.31, 315.12 and 139.75 is: 192.89

Step by Step Solution

  1. Step 1: Write the proportion equation
    228.31 : 315.12 = 139.75 : x
  2. Step 2: Convert to fraction form
    228.31/315.12 = 139.75/x
  3. Step 3: Cross multiply
    228.31x = 315.12 × 139.75
  4. Step 4: Simplify right side
    228.31x = 44,038.02
  5. Step 5: Solve for x
    x = 44,038.02/228.31
  6. Step 6: Final answer
    x = 192.89

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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.