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Finding the Fourth Proportional to 1,981.76, 2,972.64 and 1,289

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Solution

The fourth proportional to 1,981.76, 2,972.64 and 1,289 is: 1,933.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,981.76 : 2,972.64 = 1,289 : x
  2. Step 2: Convert to fraction form
    1,981.76/2,972.64 = 1,289/x
  3. Step 3: Cross multiply
    1,981.76x = 2,972.64 × 1,289
  4. Step 4: Simplify right side
    1,981.76x = 3,831,732.96
  5. Step 5: Solve for x
    x = 3,831,732.96/1,981.76
  6. Step 6: Final answer
    x = 1,933.50

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Double scale
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Similar ratio
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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.