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Finding the Fourth Proportional to 390.32, 538.96 and 307.36

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Solution

The fourth proportional to 390.32, 538.96 and 307.36 is: 424.41

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.32 : 538.96 = 307.36 : x
  2. Step 2: Convert to fraction form
    390.32/538.96 = 307.36/x
  3. Step 3: Cross multiply
    390.32x = 538.96 × 307.36
  4. Step 4: Simplify right side
    390.32x = 165,654.75
  5. Step 5: Solve for x
    x = 165,654.75/390.32
  6. Step 6: Final answer
    x = 424.41

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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.