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Finding the Fourth Proportional to 685.27, 945.75 and 390.58

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Solution

The fourth proportional to 685.27, 945.75 and 390.58 is: 539.04

Step by Step Solution

  1. Step 1: Write the proportion equation
    685.27 : 945.75 = 390.58 : x
  2. Step 2: Convert to fraction form
    685.27/945.75 = 390.58/x
  3. Step 3: Cross multiply
    685.27x = 945.75 × 390.58
  4. Step 4: Simplify right side
    685.27x = 369,391.04
  5. Step 5: Solve for x
    x = 369,391.04/685.27
  6. Step 6: Final answer
    x = 539.04

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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.