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Finding the Fourth Proportional to 646.20, 891.96 and 499.20

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Solution

The fourth proportional to 646.20, 891.96 and 499.20 is: 689.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    646.20 : 891.96 = 499.20 : x
  2. Step 2: Convert to fraction form
    646.20/891.96 = 499.20/x
  3. Step 3: Cross multiply
    646.20x = 891.96 × 499.20
  4. Step 4: Simplify right side
    646.20x = 445,266.43
  5. Step 5: Solve for x
    x = 445,266.43/646.20
  6. Step 6: Final answer
    x = 689.05

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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.