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Finding the Fourth Proportional to 390.76, 585.28 and 338.08

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Solution

The fourth proportional to 390.76, 585.28 and 338.08 is: 506.38

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.76 : 585.28 = 338.08 : x
  2. Step 2: Convert to fraction form
    390.76/585.28 = 338.08/x
  3. Step 3: Cross multiply
    390.76x = 585.28 × 338.08
  4. Step 4: Simplify right side
    390.76x = 197,871.46
  5. Step 5: Solve for x
    x = 197,871.46/390.76
  6. Step 6: Final answer
    x = 506.38

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.