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Finding the Fourth Proportional to 621.67, 857.55 and 385.51

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Solution

The fourth proportional to 621.67, 857.55 and 385.51 is: 531.78

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.67 : 857.55 = 385.51 : x
  2. Step 2: Convert to fraction form
    621.67/857.55 = 385.51/x
  3. Step 3: Cross multiply
    621.67x = 857.55 × 385.51
  4. Step 4: Simplify right side
    621.67x = 330,594.10
  5. Step 5: Solve for x
    x = 330,594.10/621.67
  6. Step 6: Final answer
    x = 531.78

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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.