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Finding the Fourth Proportional to 636.72, 953.64 and 420

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Solution

The fourth proportional to 636.72, 953.64 and 420 is: 629.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.72 : 953.64 = 420 : x
  2. Step 2: Convert to fraction form
    636.72/953.64 = 420/x
  3. Step 3: Cross multiply
    636.72x = 953.64 × 420
  4. Step 4: Simplify right side
    636.72x = 400,528.80
  5. Step 5: Solve for x
    x = 400,528.80/636.72
  6. Step 6: Final answer
    x = 629.05

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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.