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Finding the Fourth Proportional to 1,287.71, 1,776.66 and 868.53

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Solution

The fourth proportional to 1,287.71, 1,776.66 and 868.53 is: 1,198.32

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,287.71 : 1,776.66 = 868.53 : x
  2. Step 2: Convert to fraction form
    1,287.71/1,776.66 = 868.53/x
  3. Step 3: Cross multiply
    1,287.71x = 1,776.66 × 868.53
  4. Step 4: Simplify right side
    1,287.71x = 1,543,082.51
  5. Step 5: Solve for x
    x = 1,543,082.51/1,287.71
  6. Step 6: Final answer
    x = 1,198.32

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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.