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Finding the Fourth Proportional to 621.85, 857.55 and 412.21

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Solution

The fourth proportional to 621.85, 857.55 and 412.21 is: 568.45

Step by Step Solution

  1. Step 1: Write the proportion equation
    621.85 : 857.55 = 412.21 : x
  2. Step 2: Convert to fraction form
    621.85/857.55 = 412.21/x
  3. Step 3: Cross multiply
    621.85x = 857.55 × 412.21
  4. Step 4: Simplify right side
    621.85x = 353,490.69
  5. Step 5: Solve for x
    x = 353,490.69/621.85
  6. Step 6: Final answer
    x = 568.45

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Double scale
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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.