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Finding the Fourth Proportional to 990.53, 1,485.81 and 260.18

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Solution

The fourth proportional to 990.53, 1,485.81 and 260.18 is: 390.27

Step by Step Solution

  1. Step 1: Write the proportion equation
    990.53 : 1,485.81 = 260.18 : x
  2. Step 2: Convert to fraction form
    990.53/1,485.81 = 260.18/x
  3. Step 3: Cross multiply
    990.53x = 1,485.81 × 260.18
  4. Step 4: Simplify right side
    990.53x = 386,570.62
  5. Step 5: Solve for x
    x = 386,570.62/990.53
  6. Step 6: Final answer
    x = 390.27

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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.