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Finding the Fourth Proportional to 687.77, 1,031.72 and 302.81

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Solution

The fourth proportional to 687.77, 1,031.72 and 302.81 is: 454.24

Step by Step Solution

  1. Step 1: Write the proportion equation
    687.77 : 1,031.72 = 302.81 : x
  2. Step 2: Convert to fraction form
    687.77/1,031.72 = 302.81/x
  3. Step 3: Cross multiply
    687.77x = 1,031.72 × 302.81
  4. Step 4: Simplify right side
    687.77x = 312,413.62
  5. Step 5: Solve for x
    x = 312,413.62/687.77
  6. Step 6: Final answer
    x = 454.24

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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.