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Finding the Fourth Proportional to 1,271.51, 1,907.39 and 491.78

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Solution

The fourth proportional to 1,271.51, 1,907.39 and 491.78 is: 737.72

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,271.51 : 1,907.39 = 491.78 : x
  2. Step 2: Convert to fraction form
    1,271.51/1,907.39 = 491.78/x
  3. Step 3: Cross multiply
    1,271.51x = 1,907.39 × 491.78
  4. Step 4: Simplify right side
    1,271.51x = 938,016.25
  5. Step 5: Solve for x
    x = 938,016.25/1,271.51
  6. Step 6: Final answer
    x = 737.72

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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.