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Finding the Fourth Proportional to 1,205, 1,807.79 and 619.77

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Solution

The fourth proportional to 1,205, 1,807.79 and 619.77 is: 929.80

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,205 : 1,807.79 = 619.77 : x
  2. Step 2: Convert to fraction form
    1,205/1,807.79 = 619.77/x
  3. Step 3: Cross multiply
    1,205x = 1,807.79 × 619.77
  4. Step 4: Simplify right side
    1,205x = 1,120,414.01
  5. Step 5: Solve for x
    x = 1,120,414.01/1,205
  6. Step 6: Final answer
    x = 929.80

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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.