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Finding the Fourth Proportional to 817.70, 1,128.22 and 486.21

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Solution

The fourth proportional to 817.70, 1,128.22 and 486.21 is: 670.84

Step by Step Solution

  1. Step 1: Write the proportion equation
    817.70 : 1,128.22 = 486.21 : x
  2. Step 2: Convert to fraction form
    817.70/1,128.22 = 486.21/x
  3. Step 3: Cross multiply
    817.70x = 1,128.22 × 486.21
  4. Step 4: Simplify right side
    817.70x = 548,550.63
  5. Step 5: Solve for x
    x = 548,550.63/817.70
  6. Step 6: Final answer
    x = 670.84

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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.