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Finding the Fourth Proportional to 420.21, 580.84 and 322.40

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Solution

The fourth proportional to 420.21, 580.84 and 322.40 is: 445.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.21 : 580.84 = 322.40 : x
  2. Step 2: Convert to fraction form
    420.21/580.84 = 322.40/x
  3. Step 3: Cross multiply
    420.21x = 580.84 × 322.40
  4. Step 4: Simplify right side
    420.21x = 187,263.46
  5. Step 5: Solve for x
    x = 187,263.46/420.21
  6. Step 6: Final answer
    x = 445.64

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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.