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Finding the Fourth Proportional to 420.64, 629.84 and 247.16

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Solution

The fourth proportional to 420.64, 629.84 and 247.16 is: 370.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    420.64 : 629.84 = 247.16 : x
  2. Step 2: Convert to fraction form
    420.64/629.84 = 247.16/x
  3. Step 3: Cross multiply
    420.64x = 629.84 × 247.16
  4. Step 4: Simplify right side
    420.64x = 155,671.25
  5. Step 5: Solve for x
    x = 155,671.25/420.64
  6. Step 6: Final answer
    x = 370.08

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.