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Finding the Fourth Proportional to 207, 285.72 and 138

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Solution

The fourth proportional to 207, 285.72 and 138 is: 190.48

Step by Step Solution

  1. Step 1: Write the proportion equation
    207 : 285.72 = 138 : x
  2. Step 2: Convert to fraction form
    207/285.72 = 138/x
  3. Step 3: Cross multiply
    207x = 285.72 × 138
  4. Step 4: Simplify right side
    207x = 39,429.36
  5. Step 5: Solve for x
    x = 39,429.36/207
  6. Step 6: Final answer
    x = 190.48

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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.