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Finding the Fourth Proportional to 1,981.19, 2,972.31 and 665.16

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Solution

The fourth proportional to 1,981.19, 2,972.31 and 665.16 is: 997.92

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,981.19 : 2,972.31 = 665.16 : x
  2. Step 2: Convert to fraction form
    1,981.19/2,972.31 = 665.16/x
  3. Step 3: Cross multiply
    1,981.19x = 2,972.31 × 665.16
  4. Step 4: Simplify right side
    1,981.19x = 1,977,061.72
  5. Step 5: Solve for x
    x = 1,977,061.72/1,981.19
  6. Step 6: Final answer
    x = 997.92

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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.