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Finding the Fourth Proportional to 989.96, 1,485.30 and 442.10

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Solution

The fourth proportional to 989.96, 1,485.30 and 442.10 is: 663.31

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.96 : 1,485.30 = 442.10 : x
  2. Step 2: Convert to fraction form
    989.96/1,485.30 = 442.10/x
  3. Step 3: Cross multiply
    989.96x = 1,485.30 × 442.10
  4. Step 4: Simplify right side
    989.96x = 656,651.13
  5. Step 5: Solve for x
    x = 656,651.13/989.96
  6. Step 6: Final answer
    x = 663.31

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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.