Home / 1,313.60-1,812.30-789.80

Finding the Fourth Proportional to 1,313.60, 1,812.30 and 789.80

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Solution

The fourth proportional to 1,313.60, 1,812.30 and 789.80 is: 1,089.64

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,313.60 : 1,812.30 = 789.80 : x
  2. Step 2: Convert to fraction form
    1,313.60/1,812.30 = 789.80/x
  3. Step 3: Cross multiply
    1,313.60x = 1,812.30 × 789.80
  4. Step 4: Simplify right side
    1,313.60x = 1,431,354.54
  5. Step 5: Solve for x
    x = 1,431,354.54/1,313.60
  6. Step 6: Final answer
    x = 1,089.64

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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.