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Finding the Fourth Proportional to 1,280.15, 1,918.85 and 731.15

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Solution

The fourth proportional to 1,280.15, 1,918.85 and 731.15 is: 1,095.94

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,280.15 : 1,918.85 = 731.15 : x
  2. Step 2: Convert to fraction form
    1,280.15/1,918.85 = 731.15/x
  3. Step 3: Cross multiply
    1,280.15x = 1,918.85 × 731.15
  4. Step 4: Simplify right side
    1,280.15x = 1,402,967.18
  5. Step 5: Solve for x
    x = 1,402,967.18/1,280.15
  6. Step 6: Final answer
    x = 1,095.94

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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.