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Finding the Fourth Proportional to 685.30, 945.76 and 405.48

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Solution

The fourth proportional to 685.30, 945.76 and 405.48 is: 559.59

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.30 : 945.76 = 405.48 : x
  2. Step 2: Convert to fraction form
    685.30/945.76 = 405.48/x
  3. Step 3: Cross multiply
    685.30x = 945.76 × 405.48
  4. Step 4: Simplify right side
    685.30x = 383,486.76
  5. Step 5: Solve for x
    x = 383,486.76/685.30
  6. Step 6: Final answer
    x = 559.59

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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.