Home / 1,311.12-1,809.27-787.05

Finding the Fourth Proportional to 1,311.12, 1,809.27 and 787.05

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Solution

The fourth proportional to 1,311.12, 1,809.27 and 787.05 is: 1,086.08

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,311.12 : 1,809.27 = 787.05 : x
  2. Step 2: Convert to fraction form
    1,311.12/1,809.27 = 787.05/x
  3. Step 3: Cross multiply
    1,311.12x = 1,809.27 × 787.05
  4. Step 4: Simplify right side
    1,311.12x = 1,423,985.95
  5. Step 5: Solve for x
    x = 1,423,985.95/1,311.12
  6. Step 6: Final answer
    x = 1,086.08

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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.