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Finding the Fourth Proportional to 1,310.25, 1,808.15 and 720.78

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Solution

The fourth proportional to 1,310.25, 1,808.15 and 720.78 is: 994.68

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,310.25 : 1,808.15 = 720.78 : x
  2. Step 2: Convert to fraction form
    1,310.25/1,808.15 = 720.78/x
  3. Step 3: Cross multiply
    1,310.25x = 1,808.15 × 720.78
  4. Step 4: Simplify right side
    1,310.25x = 1,303,274.75
  5. Step 5: Solve for x
    x = 1,303,274.75/1,310.25
  6. Step 6: Final answer
    x = 994.68

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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.