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Finding the Fourth Proportional to 1,239.48, 1,710.50 and 687.48

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Solution

The fourth proportional to 1,239.48, 1,710.50 and 687.48 is: 948.73

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,239.48 : 1,710.50 = 687.48 : x
  2. Step 2: Convert to fraction form
    1,239.48/1,710.50 = 687.48/x
  3. Step 3: Cross multiply
    1,239.48x = 1,710.50 × 687.48
  4. Step 4: Simplify right side
    1,239.48x = 1,175,934.54
  5. Step 5: Solve for x
    x = 1,175,934.54/1,239.48
  6. Step 6: Final answer
    x = 948.73

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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.