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Finding the Fourth Proportional to 1,981.70, 2,972.96 and 665.40

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Solution

The fourth proportional to 1,981.70, 2,972.96 and 665.40 is: 998.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,981.70 : 2,972.96 = 665.40 : x
  2. Step 2: Convert to fraction form
    1,981.70/2,972.96 = 665.40/x
  3. Step 3: Cross multiply
    1,981.70x = 2,972.96 × 665.40
  4. Step 4: Simplify right side
    1,981.70x = 1,978,207.58
  5. Step 5: Solve for x
    x = 1,978,207.58/1,981.70
  6. Step 6: Final answer
    x = 998.24

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1.5x scale

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.