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Finding the Fourth Proportional to 1,269.24, 1,903.84 and 780.80

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Solution

The fourth proportional to 1,269.24, 1,903.84 and 780.80 is: 1,171.19

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,269.24 : 1,903.84 = 780.80 : x
  2. Step 2: Convert to fraction form
    1,269.24/1,903.84 = 780.80/x
  3. Step 3: Cross multiply
    1,269.24x = 1,903.84 × 780.80
  4. Step 4: Simplify right side
    1,269.24x = 1,486,518.27
  5. Step 5: Solve for x
    x = 1,486,518.27/1,269.24
  6. Step 6: Final answer
    x = 1,171.19

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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.