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Finding the Fourth Proportional to 990.11, 1,485.17 and 340.85

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Solution

The fourth proportional to 990.11, 1,485.17 and 340.85 is: 511.28

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.11 : 1,485.17 = 340.85 : x
  2. Step 2: Convert to fraction form
    990.11/1,485.17 = 340.85/x
  3. Step 3: Cross multiply
    990.11x = 1,485.17 × 340.85
  4. Step 4: Simplify right side
    990.11x = 506,220.19
  5. Step 5: Solve for x
    x = 506,220.19/990.11
  6. Step 6: Final answer
    x = 511.28

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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.