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Finding the Fourth Proportional to 390.08, 538.24 and 286.72

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Solution

The fourth proportional to 390.08, 538.24 and 286.72 is: 395.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.08 : 538.24 = 286.72 : x
  2. Step 2: Convert to fraction form
    390.08/538.24 = 286.72/x
  3. Step 3: Cross multiply
    390.08x = 538.24 × 286.72
  4. Step 4: Simplify right side
    390.08x = 154,324.17
  5. Step 5: Solve for x
    x = 154,324.17/390.08
  6. Step 6: Final answer
    x = 395.62

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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.