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Finding the Fourth Proportional to 808.78, 1,117.50 and 644.44

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Solution

The fourth proportional to 808.78, 1,117.50 and 644.44 is: 890.43

Step by Step Solution

  1. Step 1: Write the proportion equation
    808.78 : 1,117.50 = 644.44 : x
  2. Step 2: Convert to fraction form
    808.78/1,117.50 = 644.44/x
  3. Step 3: Cross multiply
    808.78x = 1,117.50 × 644.44
  4. Step 4: Simplify right side
    808.78x = 720,161.70
  5. Step 5: Solve for x
    x = 720,161.70/808.78
  6. Step 6: Final answer
    x = 890.43

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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.