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Finding the Fourth Proportional to 1,310.80, 1,808.90 and 786.83

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Solution

The fourth proportional to 1,310.80, 1,808.90 and 786.83 is: 1,085.82

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,310.80 : 1,808.90 = 786.83 : x
  2. Step 2: Convert to fraction form
    1,310.80/1,808.90 = 786.83/x
  3. Step 3: Cross multiply
    1,310.80x = 1,808.90 × 786.83
  4. Step 4: Simplify right side
    1,310.80x = 1,423,296.79
  5. Step 5: Solve for x
    x = 1,423,296.79/1,310.80
  6. Step 6: Final answer
    x = 1,085.82

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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.