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Finding the Fourth Proportional to 1,289.43, 1,779.77 and 765.77

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Solution

The fourth proportional to 1,289.43, 1,779.77 and 765.77 is: 1,056.97

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.43 : 1,779.77 = 765.77 : x
  2. Step 2: Convert to fraction form
    1,289.43/1,779.77 = 765.77/x
  3. Step 3: Cross multiply
    1,289.43x = 1,779.77 × 765.77
  4. Step 4: Simplify right side
    1,289.43x = 1,362,887.49
  5. Step 5: Solve for x
    x = 1,362,887.49/1,289.43
  6. Step 6: Final answer
    x = 1,056.97

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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.