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Finding the Fourth Proportional to 687.15, 948.35 and 388.41

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Solution

The fourth proportional to 687.15, 948.35 and 388.41 is: 536.05

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.15 : 948.35 = 388.41 : x
  2. Step 2: Convert to fraction form
    687.15/948.35 = 388.41/x
  3. Step 3: Cross multiply
    687.15x = 948.35 × 388.41
  4. Step 4: Simplify right side
    687.15x = 368,341.94
  5. Step 5: Solve for x
    x = 368,341.94/687.15
  6. Step 6: Final answer
    x = 536.05

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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.