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Finding the Fourth Proportional to 663.20, 990.46 and 555.08

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Solution

The fourth proportional to 663.20, 990.46 and 555.08 is: 828.99

Step by Step Solution

  1. Step 1: Write the proportion equation
    663.20 : 990.46 = 555.08 : x
  2. Step 2: Convert to fraction form
    663.20/990.46 = 555.08/x
  3. Step 3: Cross multiply
    663.20x = 990.46 × 555.08
  4. Step 4: Simplify right side
    663.20x = 549,784.54
  5. Step 5: Solve for x
    x = 549,784.54/663.20
  6. Step 6: Final answer
    x = 828.99

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.