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Finding the Fourth Proportional to 686.86, 1,030.20 and 253.69

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Solution

The fourth proportional to 686.86, 1,030.20 and 253.69 is: 380.50

Step by Step Solution

  1. Step 1: Write the proportion equation
    686.86 : 1,030.20 = 253.69 : x
  2. Step 2: Convert to fraction form
    686.86/1,030.20 = 253.69/x
  3. Step 3: Cross multiply
    686.86x = 1,030.20 × 253.69
  4. Step 4: Simplify right side
    686.86x = 261,351.44
  5. Step 5: Solve for x
    x = 261,351.44/686.86
  6. Step 6: Final answer
    x = 380.50

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Double scale
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1.5x scale

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.