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Finding the Fourth Proportional to 989.91, 1,485.07 and 340.70

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Solution

The fourth proportional to 989.91, 1,485.07 and 340.70 is: 511.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    989.91 : 1,485.07 = 340.70 : x
  2. Step 2: Convert to fraction form
    989.91/1,485.07 = 340.70/x
  3. Step 3: Cross multiply
    989.91x = 1,485.07 × 340.70
  4. Step 4: Simplify right side
    989.91x = 505,955.07
  5. Step 5: Solve for x
    x = 505,955.07/989.91
  6. Step 6: Final answer
    x = 511.11

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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.