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Finding the Fourth Proportional to 1,218.72, 1,681.92 and 804

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Solution

The fourth proportional to 1,218.72, 1,681.92 and 804 is: 1,109.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,218.72 : 1,681.92 = 804 : x
  2. Step 2: Convert to fraction form
    1,218.72/1,681.92 = 804/x
  3. Step 3: Cross multiply
    1,218.72x = 1,681.92 × 804
  4. Step 4: Simplify right side
    1,218.72x = 1,352,263.68
  5. Step 5: Solve for x
    x = 1,352,263.68/1,218.72
  6. Step 6: Final answer
    x = 1,109.58

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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.