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Finding the Fourth Proportional to 636.99, 955.35 and 420.72

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Solution

The fourth proportional to 636.99, 955.35 and 420.72 is: 630.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    636.99 : 955.35 = 420.72 : x
  2. Step 2: Convert to fraction form
    636.99/955.35 = 420.72/x
  3. Step 3: Cross multiply
    636.99x = 955.35 × 420.72
  4. Step 4: Simplify right side
    636.99x = 401,934.85
  5. Step 5: Solve for x
    x = 401,934.85/636.99
  6. Step 6: Final answer
    x = 630.99

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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.