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Finding the Fourth Proportional to 990.24, 1,485.69 and 442.81

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Solution

The fourth proportional to 990.24, 1,485.69 and 442.81 is: 664.36

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.24 : 1,485.69 = 442.81 : x
  2. Step 2: Convert to fraction form
    990.24/1,485.69 = 442.81/x
  3. Step 3: Cross multiply
    990.24x = 1,485.69 × 442.81
  4. Step 4: Simplify right side
    990.24x = 657,878.39
  5. Step 5: Solve for x
    x = 657,878.39/990.24
  6. Step 6: Final answer
    x = 664.36

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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.