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Finding the Fourth Proportional to 681.15, 939.95 and 386.42

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Solution

The fourth proportional to 681.15, 939.95 and 386.42 is: 533.23

Step by Step Solution

  1. Step 1: Write the proportion equation
    681.15 : 939.95 = 386.42 : x
  2. Step 2: Convert to fraction form
    681.15/939.95 = 386.42/x
  3. Step 3: Cross multiply
    681.15x = 939.95 × 386.42
  4. Step 4: Simplify right side
    681.15x = 363,208.85
  5. Step 5: Solve for x
    x = 363,208.85/681.15
  6. Step 6: Final answer
    x = 533.23

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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.