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Finding the Fourth Proportional to 979.05, 1,351.16 and 646.90

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Solution

The fourth proportional to 979.05, 1,351.16 and 646.90 is: 892.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    979.05 : 1,351.16 = 646.90 : x
  2. Step 2: Convert to fraction form
    979.05/1,351.16 = 646.90/x
  3. Step 3: Cross multiply
    979.05x = 1,351.16 × 646.90
  4. Step 4: Simplify right side
    979.05x = 874,065.40
  5. Step 5: Solve for x
    x = 874,065.40/979.05
  6. Step 6: Final answer
    x = 892.77

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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.