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Finding the Fourth Proportional to 978.25, 1,349.99 and 729.79

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Solution

The fourth proportional to 978.25, 1,349.99 and 729.79 is: 1,007.11

Step by Step Solution

  1. Step 1: Write the proportion equation
    978.25 : 1,349.99 = 729.79 : x
  2. Step 2: Convert to fraction form
    978.25/1,349.99 = 729.79/x
  3. Step 3: Cross multiply
    978.25x = 1,349.99 × 729.79
  4. Step 4: Simplify right side
    978.25x = 985,209.20
  5. Step 5: Solve for x
    x = 985,209.20/978.25
  6. Step 6: Final answer
    x = 1,007.11

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.