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Finding the Fourth Proportional to 328.59, 490.40 and 315.36

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Solution

The fourth proportional to 328.59, 490.40 and 315.36 is: 470.65

Step by Step Solution

  1. Step 1: Write the proportion equation
    328.59 : 490.40 = 315.36 : x
  2. Step 2: Convert to fraction form
    328.59/490.40 = 315.36/x
  3. Step 3: Cross multiply
    328.59x = 490.40 × 315.36
  4. Step 4: Simplify right side
    328.59x = 154,650.97
  5. Step 5: Solve for x
    x = 154,650.97/328.59
  6. Step 6: Final answer
    x = 470.65

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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.