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Finding the Fourth Proportional to 807.40, 1,205.17 and 780.36

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Solution

The fourth proportional to 807.40, 1,205.17 and 780.36 is: 1,164.81

Step by Step Solution

  1. Step 1: Write the proportion equation
    807.40 : 1,205.17 = 780.36 : x
  2. Step 2: Convert to fraction form
    807.40/1,205.17 = 780.36/x
  3. Step 3: Cross multiply
    807.40x = 1,205.17 × 780.36
  4. Step 4: Simplify right side
    807.40x = 940,466.46
  5. Step 5: Solve for x
    x = 940,466.46/807.40
  6. Step 6: Final answer
    x = 1,164.81

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Why These Related Problems?

These problems maintain the same ratio (1.49) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.