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Finding the Fourth Proportional to 420.48, 628.03 and 328.19

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Solution

The fourth proportional to 420.48, 628.03 and 328.19 is: 490.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.48 : 628.03 = 328.19 : x
  2. Step 2: Convert to fraction form
    420.48/628.03 = 328.19/x
  3. Step 3: Cross multiply
    420.48x = 628.03 × 328.19
  4. Step 4: Simplify right side
    420.48x = 206,113.17
  5. Step 5: Solve for x
    x = 206,113.17/420.48
  6. Step 6: Final answer
    x = 490.19

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Double scale
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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.