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Finding the Fourth Proportional to 328.48, 490.31 and 285.45

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Solution

The fourth proportional to 328.48, 490.31 and 285.45 is: 426.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.48 : 490.31 = 285.45 : x
  2. Step 2: Convert to fraction form
    328.48/490.31 = 285.45/x
  3. Step 3: Cross multiply
    328.48x = 490.31 × 285.45
  4. Step 4: Simplify right side
    328.48x = 139,958.99
  5. Step 5: Solve for x
    x = 139,958.99/328.48
  6. Step 6: Final answer
    x = 426.08

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.