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Finding the Fourth Proportional to 1,289.18, 1,779.08 and 699.72

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Solution

The fourth proportional to 1,289.18, 1,779.08 and 699.72 is: 965.62

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.18 : 1,779.08 = 699.72 : x
  2. Step 2: Convert to fraction form
    1,289.18/1,779.08 = 699.72/x
  3. Step 3: Cross multiply
    1,289.18x = 1,779.08 × 699.72
  4. Step 4: Simplify right side
    1,289.18x = 1,244,857.86
  5. Step 5: Solve for x
    x = 1,244,857.86/1,289.18
  6. Step 6: Final answer
    x = 965.62

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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.