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Finding the Fourth Proportional to 1,278.05, 1,912.14 and 865.22

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Solution

The fourth proportional to 1,278.05, 1,912.14 and 865.22 is: 1,294.49

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,278.05 : 1,912.14 = 865.22 : x
  2. Step 2: Convert to fraction form
    1,278.05/1,912.14 = 865.22/x
  3. Step 3: Cross multiply
    1,278.05x = 1,912.14 × 865.22
  4. Step 4: Simplify right side
    1,278.05x = 1,654,412.21
  5. Step 5: Solve for x
    x = 1,654,412.21/1,278.05
  6. Step 6: Final answer
    x = 1,294.49

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1.5x scale

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.