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Finding the Fourth Proportional to 990.25, 1,485.20 and 442.33

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Solution

The fourth proportional to 990.25, 1,485.20 and 442.33 is: 663.42

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.25 : 1,485.20 = 442.33 : x
  2. Step 2: Convert to fraction form
    990.25/1,485.20 = 442.33/x
  3. Step 3: Cross multiply
    990.25x = 1,485.20 × 442.33
  4. Step 4: Simplify right side
    990.25x = 656,945.91
  5. Step 5: Solve for x
    x = 656,945.91/990.25
  6. Step 6: Final answer
    x = 663.42

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1.5x scale

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.