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Finding the Fourth Proportional to 780.09, 1,169.66 and 259.95

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Solution

The fourth proportional to 780.09, 1,169.66 and 259.95 is: 389.77

Step by Step Solution

  1. Step 1: Write the proportion equation
    780.09 : 1,169.66 = 259.95 : x
  2. Step 2: Convert to fraction form
    780.09/1,169.66 = 259.95/x
  3. Step 3: Cross multiply
    780.09x = 1,169.66 × 259.95
  4. Step 4: Simplify right side
    780.09x = 304,053.12
  5. Step 5: Solve for x
    x = 304,053.12/780.09
  6. Step 6: Final answer
    x = 389.77

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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.