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Finding the Fourth Proportional to 328.28, 455.17 and 318.71

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Solution

The fourth proportional to 328.28, 455.17 and 318.71 is: 441.90

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.28 : 455.17 = 318.71 : x
  2. Step 2: Convert to fraction form
    328.28/455.17 = 318.71/x
  3. Step 3: Cross multiply
    328.28x = 455.17 × 318.71
  4. Step 4: Simplify right side
    328.28x = 145,066.89
  5. Step 5: Solve for x
    x = 145,066.89/328.28
  6. Step 6: Final answer
    x = 441.90

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Why These Related Problems?

These problems maintain the same ratio (1.39) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.