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Finding the Fourth Proportional to 990.49, 1,485.79 and 442.71

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Solution

The fourth proportional to 990.49, 1,485.79 and 442.71 is: 664.09

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.49 : 1,485.79 = 442.71 : x
  2. Step 2: Convert to fraction form
    990.49/1,485.79 = 442.71/x
  3. Step 3: Cross multiply
    990.49x = 1,485.79 × 442.71
  4. Step 4: Simplify right side
    990.49x = 657,774.09
  5. Step 5: Solve for x
    x = 657,774.09/990.49
  6. Step 6: Final answer
    x = 664.09

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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.