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Finding the Fourth Proportional to 1,268.12, 1,902.60 and 618.80

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Solution

The fourth proportional to 1,268.12, 1,902.60 and 618.80 is: 928.40

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,268.12 : 1,902.60 = 618.80 : x
  2. Step 2: Convert to fraction form
    1,268.12/1,902.60 = 618.80/x
  3. Step 3: Cross multiply
    1,268.12x = 1,902.60 × 618.80
  4. Step 4: Simplify right side
    1,268.12x = 1,177,328.88
  5. Step 5: Solve for x
    x = 1,177,328.88/1,268.12
  6. Step 6: Final answer
    x = 928.40

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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.