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Finding the Fourth Proportional to 1,389.08, 2,083.54 and 781.08

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Solution

The fourth proportional to 1,389.08, 2,083.54 and 781.08 is: 1,171.58

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.08 : 2,083.54 = 781.08 : x
  2. Step 2: Convert to fraction form
    1,389.08/2,083.54 = 781.08/x
  3. Step 3: Cross multiply
    1,389.08x = 2,083.54 × 781.08
  4. Step 4: Simplify right side
    1,389.08x = 1,627,411.42
  5. Step 5: Solve for x
    x = 1,627,411.42/1,389.08
  6. Step 6: Final answer
    x = 1,171.58

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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.