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Finding the Fourth Proportional to 1,289.30, 1,779.21 and 699.83

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Solution

The fourth proportional to 1,289.30, 1,779.21 and 699.83 is: 965.75

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.30 : 1,779.21 = 699.83 : x
  2. Step 2: Convert to fraction form
    1,289.30/1,779.21 = 699.83/x
  3. Step 3: Cross multiply
    1,289.30x = 1,779.21 × 699.83
  4. Step 4: Simplify right side
    1,289.30x = 1,245,142.31
  5. Step 5: Solve for x
    x = 1,245,142.31/1,289.30
  6. Step 6: Final answer
    x = 965.75

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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.