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Finding the Fourth Proportional to 1,376.70, 1,899.84 and 787.20

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Solution

The fourth proportional to 1,376.70, 1,899.84 and 787.20 is: 1,086.33

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,376.70 : 1,899.84 = 787.20 : x
  2. Step 2: Convert to fraction form
    1,376.70/1,899.84 = 787.20/x
  3. Step 3: Cross multiply
    1,376.70x = 1,899.84 × 787.20
  4. Step 4: Simplify right side
    1,376.70x = 1,495,554.05
  5. Step 5: Solve for x
    x = 1,495,554.05/1,376.70
  6. Step 6: Final answer
    x = 1,086.33

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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.