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Finding the Fourth Proportional to 1,320.42, 1,983.51 and 807.78

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Solution

The fourth proportional to 1,320.42, 1,983.51 and 807.78 is: 1,213.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,320.42 : 1,983.51 = 807.78 : x
  2. Step 2: Convert to fraction form
    1,320.42/1,983.51 = 807.78/x
  3. Step 3: Cross multiply
    1,320.42x = 1,983.51 × 807.78
  4. Step 4: Simplify right side
    1,320.42x = 1,602,239.71
  5. Step 5: Solve for x
    x = 1,602,239.71/1,320.42
  6. Step 6: Final answer
    x = 1,213.43

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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.