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Finding the Fourth Proportional to 1,219.82, 1,681.71 and 869.90

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Solution

The fourth proportional to 1,219.82, 1,681.71 and 869.90 is: 1,199.29

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,219.82 : 1,681.71 = 869.90 : x
  2. Step 2: Convert to fraction form
    1,219.82/1,681.71 = 869.90/x
  3. Step 3: Cross multiply
    1,219.82x = 1,681.71 × 869.90
  4. Step 4: Simplify right side
    1,219.82x = 1,462,919.53
  5. Step 5: Solve for x
    x = 1,462,919.53/1,219.82
  6. Step 6: Final answer
    x = 1,199.29

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.