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Finding the Fourth Proportional to 663.68, 913.20 and 646.72

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Solution

The fourth proportional to 663.68, 913.20 and 646.72 is: 889.86

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.68 : 913.20 = 646.72 : x
  2. Step 2: Convert to fraction form
    663.68/913.20 = 646.72/x
  3. Step 3: Cross multiply
    663.68x = 913.20 × 646.72
  4. Step 4: Simplify right side
    663.68x = 590,584.70
  5. Step 5: Solve for x
    x = 590,584.70/663.68
  6. Step 6: Final answer
    x = 889.86

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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.