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Finding the Fourth Proportional to 1,943.78, 2,915.60 and 645.21

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Solution

The fourth proportional to 1,943.78, 2,915.60 and 645.21 is: 967.79

Step by Step Solution

  1. Step 1: Write the proportion equation
    1,943.78 : 2,915.60 = 645.21 : x
  2. Step 2: Convert to fraction form
    1,943.78/2,915.60 = 645.21/x
  3. Step 3: Cross multiply
    1,943.78x = 2,915.60 × 645.21
  4. Step 4: Simplify right side
    1,943.78x = 1,881,171.05
  5. Step 5: Solve for x
    x = 1,881,171.05/1,943.78
  6. Step 6: Final answer
    x = 967.79

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1.5x scale

Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.