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Finding the Fourth Proportional to 1,318.30, 1,818.03 and 820.75

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Solution

The fourth proportional to 1,318.30, 1,818.03 and 820.75 is: 1,131.87

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,318.30 : 1,818.03 = 820.75 : x
  2. Step 2: Convert to fraction form
    1,318.30/1,818.03 = 820.75/x
  3. Step 3: Cross multiply
    1,318.30x = 1,818.03 × 820.75
  4. Step 4: Simplify right side
    1,318.30x = 1,492,148.12
  5. Step 5: Solve for x
    x = 1,492,148.12/1,318.30
  6. Step 6: Final answer
    x = 1,131.87

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1.5x scale

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.