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Finding the Fourth Proportional to 1,389.85, 1,917.95 and 800.39

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Solution

The fourth proportional to 1,389.85, 1,917.95 and 800.39 is: 1,104.52

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,389.85 : 1,917.95 = 800.39 : x
  2. Step 2: Convert to fraction form
    1,389.85/1,917.95 = 800.39/x
  3. Step 3: Cross multiply
    1,389.85x = 1,917.95 × 800.39
  4. Step 4: Simplify right side
    1,389.85x = 1,535,108.79
  5. Step 5: Solve for x
    x = 1,535,108.79/1,389.85
  6. Step 6: Final answer
    x = 1,104.52

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.