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Finding the Fourth Proportional to 868.86, 1,299.65 and 661.10

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Solution

The fourth proportional to 868.86, 1,299.65 and 661.10 is: 988.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    868.86 : 1,299.65 = 661.10 : x
  2. Step 2: Convert to fraction form
    868.86/1,299.65 = 661.10/x
  3. Step 3: Cross multiply
    868.86x = 1,299.65 × 661.10
  4. Step 4: Simplify right side
    868.86x = 859,188.81
  5. Step 5: Solve for x
    x = 859,188.81/868.86
  6. Step 6: Final answer
    x = 988.87

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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.