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Finding the Fourth Proportional to 420.04, 578.92 and 287.16

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Solution

The fourth proportional to 420.04, 578.92 and 287.16 is: 395.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.04 : 578.92 = 287.16 : x
  2. Step 2: Convert to fraction form
    420.04/578.92 = 287.16/x
  3. Step 3: Cross multiply
    420.04x = 578.92 × 287.16
  4. Step 4: Simplify right side
    420.04x = 166,242.67
  5. Step 5: Solve for x
    x = 166,242.67/420.04
  6. Step 6: Final answer
    x = 395.78

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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.