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Finding the Fourth Proportional to 390.41, 538.14 and 307.38

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Solution

The fourth proportional to 390.41, 538.14 and 307.38 is: 423.70

Step by Step Solution

  1. Step 1: Write the proportion equation
    390.41 : 538.14 = 307.38 : x
  2. Step 2: Convert to fraction form
    390.41/538.14 = 307.38/x
  3. Step 3: Cross multiply
    390.41x = 538.14 × 307.38
  4. Step 4: Simplify right side
    390.41x = 165,416.64
  5. Step 5: Solve for x
    x = 165,416.64/390.41
  6. Step 6: Final answer
    x = 423.70

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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.