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Finding the Fourth Proportional to 1,211.19, 1,817.60 and 778.65

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Solution

The fourth proportional to 1,211.19, 1,817.60 and 778.65 is: 1,168.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,211.19 : 1,817.60 = 778.65 : x
  2. Step 2: Convert to fraction form
    1,211.19/1,817.60 = 778.65/x
  3. Step 3: Cross multiply
    1,211.19x = 1,817.60 × 778.65
  4. Step 4: Simplify right side
    1,211.19x = 1,415,274.24
  5. Step 5: Solve for x
    x = 1,415,274.24/1,211.19
  6. Step 6: Final answer
    x = 1,168.50

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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.