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Finding the Fourth Proportional to 687, 1,030.40 and 254.08

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Solution

The fourth proportional to 687, 1,030.40 and 254.08 is: 381.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    687 : 1,030.40 = 254.08 : x
  2. Step 2: Convert to fraction form
    687/1,030.40 = 254.08/x
  3. Step 3: Cross multiply
    687x = 1,030.40 × 254.08
  4. Step 4: Simplify right side
    687x = 261,804.03
  5. Step 5: Solve for x
    x = 261,804.03/687
  6. Step 6: Final answer
    x = 381.08

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.