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Finding the Fourth Proportional to 1,289.78, 1,779.93 and 758.70

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Solution

The fourth proportional to 1,289.78, 1,779.93 and 758.70 is: 1,047.02

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,289.78 : 1,779.93 = 758.70 : x
  2. Step 2: Convert to fraction form
    1,289.78/1,779.93 = 758.70/x
  3. Step 3: Cross multiply
    1,289.78x = 1,779.93 × 758.70
  4. Step 4: Simplify right side
    1,289.78x = 1,350,420.20
  5. Step 5: Solve for x
    x = 1,350,420.20/1,289.78
  6. Step 6: Final answer
    x = 1,047.02

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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.