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Finding the Fourth Proportional to 1,268.79, 1,901.10 and 780.81

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Solution

The fourth proportional to 1,268.79, 1,901.10 and 780.81 is: 1,169.93

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,268.79 : 1,901.10 = 780.81 : x
  2. Step 2: Convert to fraction form
    1,268.79/1,901.10 = 780.81/x
  3. Step 3: Cross multiply
    1,268.79x = 1,901.10 × 780.81
  4. Step 4: Simplify right side
    1,268.79x = 1,484,397.89
  5. Step 5: Solve for x
    x = 1,484,397.89/1,268.79
  6. Step 6: Final answer
    x = 1,169.93

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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.