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Finding the Fourth Proportional to 699.20, 979.60 and 699.20

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Solution

The fourth proportional to 699.20, 979.60 and 699.20 is: 979.60

Step by Step Solution

  1. Step 1: Write the proportion equation
    699.20 : 979.60 = 699.20 : x
  2. Step 2: Convert to fraction form
    699.20/979.60 = 699.20/x
  3. Step 3: Cross multiply
    699.20x = 979.60 × 699.20
  4. Step 4: Simplify right side
    699.20x = 684,936.32
  5. Step 5: Solve for x
    x = 684,936.32/699.20
  6. Step 6: Final answer
    x = 979.60

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.40) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.